Potatoes Au Gratin

4.98 from 143 votes
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This delicious potatoes au gratin recipe is easy to make during the holidays. It’s the perfect cheesy potato side dish that complements any meal.

Spoon lifting potatoes au gratin from a casserole dish.

Recipe Science

  • Choose waxy Yukon gold potatoes. The flesh is buttery and holds its shape well when scooped and served, preserving the layers.
  • Gruyere melts smoothly with a nutty flavor, while sharp cheddar provides bold, aged notes. They enhance the bechamel’s creaminess and create a golden, gooey crust.
  • A roux prevents the milk from curdling by stabilizing the sauce during baking and adds creaminess for better texture.

Why It Works

Creamy, cheesy potatoes au gratin are a classic, crowd-pleasing side dish that’s easy to make—unless the cream curdles or the potatoes don’t turn out fork-tender. With the right tips, I’ll show you how to avoid these common issues for perfect results.

This potato au gratin recipe uses multiple layers of thinly sliced Yukon gold potatoes topped with a roux-based sauce to stabilize the milk in the dish. Aged sharp cheddar and buttery gruyere cheese are mixed in the sauce and sprinkled on the potatoes. It’s a comforting dish that can be prepared ahead of time and enjoyed later.

Ingredients You’ll Need

  • Potatoes: For au gratin, choose a medium-sized waxy type of potato like Yukon gold potatoes. Once cooked, the flesh has a buttery texture and holds its shape well when scooping out each serving.
  • Cheese: The best cheese combination for the au gratin potatoes is gruyere and sharp cheddar cheese. Gruyere is a medium-hard cheese with a nutty taste and a hint of sweetness. It has excellent melting properties, and I always use it when making French onion soup. Sharp cheddar has a stronger aged flavor and a semi-hard texture. Together they melt effortlessly in the bechamel sauce and create a nice gooey, browned crust on top of the potatoes.
  • Alliums: Minced garlic and chopped yellow onions are sauteed in butter to build a savory and earthy base for the cream sauce.
  • Cream Sauce: The basic technique for creating a milk sauce is using a thickening agent, like a roux. This recipe uses equal parts by volume of butter and flour, which cooks into a paste. Then, gradually incorporate milk while simmering until the thickness coats a spoon. It’s seasoned with salt, black pepper, and nutmeg.
  • Herbs: Chives garnish the potato side dish and add a delicate onion flavor.

See the recipe card below for all ingredients and measurements (US and metric).

Ingredient Substitutions

This au gratin potatoes recipe is easy to customize! Try these tasty options:

  • Potato Substitutes: Russets are my second choice because their delicate texture tends to absorb the sauce and become too creamy. I prefer to use Russet potatoes for mashed potatoes instead. Red potatoes can also be used for a waxy texture.
  • Make the Sauce Creamier: You can use heavy cream for a richer consistency.
  • Cheese Swaps: Use shredded cheeses that melt well, like Swiss cheese, gouda, or mozzarella. Add some parmesan cheese for a nutty flavor.
  • Herbs: Garnish with fresh herbs like chopped parsley, thyme, rosemary, tarragon, or green onions.
  • Add Meat: Sprinkle on smoky roasted bacon, pancetta, or make scalloped potatoes with ham.

How to Make Au Gratin Potatoes

Step 1: Preheat the Oven

Position your oven rack in the center to ensure even baking, then preheat to 400ºF (200ºC). This temperature allows the potatoes to cook through while developing a beautifully golden brown, bubbly top.

Incorporating flour into a pan with butter, onions, and garlic.

Step 2: Make the Cream Sauce
Melt butter in a skillet over medium-low heat, then sauté garlic and onions until fragrant, about 2 minutes. Stir in flour and cook for 2 minutes.

Whisking salt, pepper, and nutmeg into a pan of cream sauce.

Gradually whisk in the milk, cooking until thickened, 2 to 3 minutes. Turn off the heat and season with salt, pepper, and nutmeg. This creates a smooth, flavorful sauce for your potatoes.

Ingredient Chemistry: If you only add milk to the potatoes, the proteins are at risk of curdling over time. Once the protein hits a temperature of 180ºF (82ºC) and above, they begin clumping together. Considering the potatoes are cooked at 400ºF (204ºC) for nearly an hour to tenderize, it’s best to build a little safety cushion with a roux. The creamy texture added to the sauce is just a tasty bonus!

Two types of cheeses being whisked into a roux-based pan sauce.

Step 3: Add the Cheese

Stir in Gruyere and sharp cheddar cheese until melted and combined, creating a rich, cheesy bechamel sauce. This technique is also used in macaroni and cheese, but we use potatoes instead of pasta. If made correctly, the sauce should spread easily between the potato layers instead of pooling at the bottom of the baking dish.

Sliced potatoes lined up in a casserole dish.

Step 4: Assemble the Casserole

In a greased 8-inch square baking dish, layer half the potatoes, overlapping them.

Grated pieces of gruyere and sharp cheddar cheese sprinkled on top of uncooked potatoes au gratin casserole.

Spread half of the cheese sauce and shredded cheese. Repeat the layering once more time with the remaining ingredients.

Step 5: Bake

Cover the dish with foil and bake in a preheated oven at 400ºF (200ºC). This traps the heat to steam and softens the spuds. After 30 minutes, remove the foil so that the cheese layer browns. Cook for about 20 to 25 minutes or until the potatoes are tender.

Potatoes au gratin hot and fresh from the oven.

Step 6: To Serve

Allow the casserole to cool on a wire rack for 10 to 15 minutes before serving. This helps the layers set. Garnish the potatoes with fresh chives. This side dish is delicious with roast turkey for Thanksgiving or roasted chicken any day of the week.

Frequently Asked Questions

What does gratin mean in French cooking?

In French cooking, “gratin” refers to a dish topped with breadcrumbs, cheese, or both and baked until it forms a golden, crispy crust. The word “gratin” comes from the French term “gratter,” meaning “to scrape,” which traditionally refers to scraping off the crispy top layer. This technique is used to add both texture and flavor to dishes like potatoes au gratin.

What’s the difference between scalloped potatoes and au gratin potatoes?

Scalloped potatoes are traditionally cut into thicker rounds, about ¼-inch, layered, and baked in a casserole dish. Cream, milk (or both), and aromatics like garlic, onions, and herbs are added. On the other hand, Au gratin has thinly sliced potatoes, ⅛-inch thick potato slices, and cheese added to the recipe. You might see breadcrumbs sprinkled on top for extra crunch. The culinary terms are often used interchangeably, which causes a bit of confusion.

How do you make creamy au gratin potatoes?

To make creamy au gratin potatoes, start by creating a roux-based sauce. The flour in the roux helps stabilize the cream sauce by thickening it as it bakes. The starches in the flour hold onto the water in the milk, preventing the oils and fats from separating, which keeps the sauce smooth and creamy. As the starches heat up, they swell, creating a rich, velvety texture that perfectly coats the potatoes.

Can the potatoes au gratin be made in advance?

This side dish can be assembled two days ahead, covered, and refrigerated until ready to bake. Bake time may need to be slightly increased as the pan and ingredients will be cold.

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If you tried this Potatoes Au Gratin Recipe, please leave a 🌟 star rating and let me know how it went in the 📝 comments below!

Potatoes Au Gratin

Potatoes au gratin casserole recipe with layers of thinly sliced Yukon gold spuds and a cream sauce that includes melted cheese.
4.98 from 143 votes
Prep Time20 minutes
Cook Time1 hour
Total Time1 hour 20 minutes
Servings 8 servings
Course Side
Cuisine French

Ingredients 
 

  • ¼ cup unsalted butter
  • 1 tablespoon minced garlic
  • ½ cup finely chopped yellow onion
  • ¼ cup all-purpose flour
  • 2 cups whole milk
  • ¾ teaspoon kosher salt
  • ½ teaspoon black pepper
  • teaspoon nutmeg
  • 2 pounds yukon gold potatoes, peeled, cut into ⅛" thick slices
  • 1 cup shredded gruyere cheese
  • 1 cup shredded sharp cheddar cheese
  • 2 teaspoon chopped chives

Instructions 

  • Preheat the Oven – Set the oven rack to the middle position. Heat to 400ºF (200ºC).
  • Make the Cream Sauce – Melt the butter in a large skillet over medium-low heat. Add garlic and onions, and saute until fragrant, 2 minutes. Add flour, whisk to combine, stir and cook for 2 minutes. Gradually whisk in milk and cook until thickened over medium heat, 2 to 3 minutes. Turn off the heat and whisk in salt, pepper, and nutmeg.
  • Add the Cheeses – Add ½ cup gruyere and ½ cup sharp cheddar cheese, and stir to combine.
  • Assemble the Casserole – Grease the bottom and sides of an 8-inch square casserole dish. Layer half of the potatoes in overlapping rows in the dish. Spread half of the cheese sauce over the potatoes. Sprinkle ¼ cup gruyere and ¼ cup cheddar over the sauce. Layer the remaining potatoes, followed by the cheese sauce, and sprinkle with the remaining gruyere and cheddar cheese.
  • Bake – Cover with foil and place on a baking sheet. Bake for 30 minutes. Remove the foil and continue baking until the potatoes are tender and the cheese is browned and bubbly, 20 to 25 minutes.
  • To Serve – Transfer the casserole to cool on a wire rack for 10 to 15 minutes before serving. Garnish potatoes with chives.

Notes

  • Make Ahead: Assemble, cover, and refrigerate for 2 days before baking. More baking time may be needed as the ingredients and pan will be cold.
  • Storing: Store in an airtight container in the refrigerator for up to 5 days. Freeze for up to 1 month.
  • Reheating: Cover and reheat a small portion in the microwave on a high setting in 15 to 30-second increments until hot. Alternatively, cover and reheat in the oven at 350ºF (177ºC) until hot.

Nutrition Facts

Serves: 8 servings
Calories 168kcal (8%)Carbohydrates 20g (7%)Protein 5g (10%)Fat 7g (11%)Saturated Fat 4g (20%)Cholesterol 21mg (7%)Sodium 256mg (11%)Potassium 548mg (16%)Fiber 2g (8%)Sugar 3g (3%)Vitamin A 275IU (6%)Vitamin C 13mg (16%)Calcium 105mg (11%)Iron 3.9mg (22%)

Percent Daily Values are based on a 2000-calorie diet. All nutritional information is based on estimated third-party calculations. Each recipe and nutritional value will vary depending on the brands you use, measuring methods, and portion sizes per household.

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Jessica Gavin

I'm a culinary school graduate, cookbook author, and a mom who loves croissants! My passion is creating recipes and sharing the science behind cooking to help you gain confidence in the kitchen.

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4.98 from 143 votes (115 ratings without comment)

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45 Comments Leave a comment or review

  1. Maria T. says

    Had this last with BBQ steak and salad. Absolutely delicious. I used the recommended Gruyere and sharp Cheddar for their great flavor and Yukon Gold for their texture. Not so time consuming with a mandolin. Always very careful. I made this dish earlier in the day, which worked out perfectly.

    • Jessica Gavin says

      Wow, the steak and potatoes combination sounds lovely! I’m glad that you found this potato recipe easy to prepare. Bravo Maria!

  2. Laura says

    Omg, this is fantastic! I followed the recipe exactly with only a pan shape differentiation (I had round and tall, not square) which resulted in a longer bake time. But the flavor! Wow. Just wow. Thank you for this awesome recipe!

  3. AQ says

    Hi Jessica
    Can I prep and freeze this casserole a few weeks ahead of thanksgiving and thaw it the night before and freeze day of or bake frozen the day of?
    Pl lmk
    Thanks in advance.

    • Jessica Gavin says

      Yes, you can prep, freeze, then defrost the casserole in the refrigerator the night before. You could bake from frozen, but it will take a lot longer to account for defrosting the ingredients in the oven.

  4. Shandi says

    Hi Jessica, is it possible to completely assemble this dish, cover tightly and freeze it. Then bake it frozen the day of? Or should I make it, bake it, then freeze it and re-heat the day of? I’m just trying to do as much ahead of Thanksgiving as possible. Thanks for your help!

    • Jessica Gavin says

      If you are baking the casserole within 2 days, I would cover it tightly then refrigerate it, they bake the day of. Let me know how it goes!

  5. Uris says

    What can I use to sub cheddar cheese? My mom gets migraines with cheddar unfortunately! 🙁 thank you!

  6. Judy Caywood says

    Jessica, I love all the science and share these with our youngest son who is interested in all the food science too. Plus you use two of my favorite cheeses!

  7. Jeannie says

    Hands down, BEST Au Gratin Recipe ever!! I’ve been cooking for 50 years and thought I made the best, but I stand corrected!! YOURS are the best!! Thank you for my new recipe! We’ve dubbed them “Holiday Potatoes “ ❤️

    • Jessica Gavin says

      Wow, that a compliment! Thank you for making the potato recipe, so thrilled to hear that you enjoyed it!

  8. Celeste says

    I doubled this recipe for a gathering of friends last night. It was dynamite and got rave reviews! No leftovers. It tasted like a gourmet side dish served at a Michelin 5-star restaurant. It took me longer than 20 minutes to prepare, however. More like 40 minutes because of slicing so many potatoes and grating cheese. I had never made a roux before so I probably worked more slowly than needed. Anyway, it turned out beautifully and I’ll be making this again for holiday dinners.

  9. Lori says

    I made this recipe yesterday and it was a HUGE hit in my house. Very flavorful and creamy. Thanks very much!

  10. Cerrina Jensen says

    My husband said this was my best au gratin ever. I wanted to up my game and looked at about 7-8 versions before picking this one. Score! ???

  11. Jen says

    In the part before the recipe you say to use milk AND cream so the sauce does curdle but the recipe has no mention of cream. Would you add cream or sub half of the amount of milk for cream?

    • Jessica Gavin says

      Hi Hen- FOr this recipe we use a flour-based roux to help stabilize the milk base. The starches help stabilize the emulsion. I was just comparing why for other recipes they might use a combo of milk and cream if you’re not using flour. You don’t have to add additional cream. Sorry for the confusion!

  12. Susan George says

    I made the Potatoes au Gratin for the ladies at the retirement where I live. They were a huge success. The only thing I have to say is ” where do you get the idea that the prep work takes 20 minutes.? It took me at least a half hour jsy to grate the Gruyere, not to mention the sharp cheddar. Then peal and slice the potatoes, make the cream sauce. I’m so glad I started the “prep” time 3 hrs. before I put it in the oven. I wish all of the recipes I looked at on your page gave a more realistic prep time. I also made the green beans with almond, again delicious and well received, but 10 minutes prep time? Are you kidding me? Just grating the orange rind and squeeze juice took longer then that. I don’t have a modern kitchen, or a ” sous chef”, all my work is done by hand myself with my 73 year old hands and arms. I will keep these recipes and probably make them again as they were so good, I just wish they were written with real people in mind.

  13. Kathy E. says

    This was a fantastic side dish for our Christmas dinner! It went perfectly with our ham and other sides. I used fat-free half and half mixed with skim milk and the sauce was still thick and so rich. It was the only dish that was completely emptied! Thank you for a winner!

  14. Ryan Haley says

    This method is perfect, I’ve been using it for years and it’s so consistent! I’m wondering if you’ve ever assembled it the night before baking? I’m concerned that the potatoes might oxidize and leave me with grey au gratin? ?

    • Jessica Gavin says

      Yukon gold potatoes don’t oxidize are severe as russets. As long as you cover it in the sauce, cheese, and tightly cover in foil in the refrigerator you can assemble it the night before.

  15. JB says

    Has anyone made this recipe the day before and just popped it in the over before dinner? If so how did it turn out..also..if cladding cream do I just substitute for milk or add to the milk?

    • Jessica Gavin says

      Hi There! I think you can assemble everything and then bake with the unmelted cheese before serving, just test to make sure the potatoes are warmed through since it will be refrigerated. What is cladding cream?

      • JB says

        Sorry not cladding …I meant using cream…if I’m using cream so I substitute one for one with milk or add cream in addition to the milk

  16. Alysa says

    Do not make this ahead of time and refrigerate overnight. The potatoes will turn brown. Trust me, I did this and they looked terrible.

    • Jessica Gavin says

      Hi Alysa! What part did you make ahead? Was it the entire recipe, or did you just slice the potatoes? Sliced potatoes will turn brown when exposed to air if not submerged in water, or cooked within a few hours (or less!).

  17. DawneSN says

    The recipe looked excellent, especially because you include nutmeg. I made it yesterday ahead of time, put in in the fridge, about 2 hours before dinner baked it beginning at 350 then moved it up to 400 for the last hour with foil on top until the last half hour. I liked that discoloration was not much of a problem as the sauce covered the potatoes well.

    I changed the recipe a bit because I didn’t have Swiss cheese, sadly, so used a merlot cheddar and a well aged white cheddar. I also doubled the onions and could have doubled them again. I thought the dish was bland. I’d make it again, but I’d add more salt and pepper and more nutmeg (mine was not super fresh).

    Our guest loved it and my husband and I added more salt and pepper.

  18. Carmelite Lofton says

    Hello Jessica
    This was my first time making this dish. I cut the recipe in half because I didn’t need to feed eight. It was perfect and easy and absolutely delicious! I did use smoked Gouda cheese instead of the Gruyere! I am so excited how tasty this dish was and can’t wait to serve it when my family comes for a visit. I look forward to checking out some other recipes!

    Thanks Again

  19. Kim says

    These were a HUGE hit for yesterday’s Easter dinner! My son was so disappointed that there were not enough for leftovers!

  20. Gwyneth Nicholson says

    Can I make this the night before through step 8, then pop it into the oven an hour before Easter dinner?

  21. Whit says

    Well I haven’t made au gratin potatoes since my husband and I got married 9 years ago. Let’s just say it was bad… really bad. Although I could barely make fried chicken let alone au gratin potatoes. I now am far enough I make my own bread and generally cook most everything we eat as fresh as I can. He’s been asking for them lately and I’ve been a little hesitant to say the least. This was a very thorough and easy to follow recipe. I thought it turned out excellent. Thank you. This is one I’ll definitely be writing down.

  22. Judy says

    Hey Jessica,
    I made this recipe last night. My husband kept commenting on how delicious it is and that he was amazed what a good choice both cheeses are in there. : ) Thanks for helping me look like a fabulous cook although I always give you the credit for all these fantastic recipes.
    Judy

  23. Tomiko says

    I can hardly wait… the potato dish is baking for large crowd tomorrow (moch-making crowd), so, I needed this recipe today. Always wondered about previous recipes where curdling occurred. I appreciate the lessons.

  24. Judy says

    Another knockout recipe Jessica. Beautiful, can taste it with my eyes. Definitely sharing with my boys who like to cook. I ordered my youngest your cookbook for Christmas. He is a brainiac and will enjoy the science.
    Thank you
    Judy