Breakfast casserole with savory pieces of ham, potatoes, bell peppers, and onions, all baked into a deliciously cheesy egg custard. The ultimate Christmas morning recipe to feed a family or portion out for meal prep during the week.
For more make-ahead breakfast recipes, try my French toast casserole and delicious quiche lorraine.
Starting the day off with a satisfying meal is essential. This super easy breakfast casserole consists of eggs, protein, vegetables, and shredded cheese. It’s a tasty gluten-free meal that can be easily tailored to meet dietary needs. Just note that the ratio of filling to egg is key to balancing the various tastes and textures. After a few chops and stirs, watch the egg mixture transform into a big pan of savory souffle with a golden crust.
Baked egg dishes tend to have issues with becoming too rubbery or watery after cooking. This is especially the case when high-moisture vegetables or dense meats are in the mixture—sautéing the potatoes and vegetables before baking helps to dry the food and concentrate flavors. Adding cornstarch to the egg base ensures that each bite stays light and custardy while keeping the filling suspended.
Sauté the vegetables and meat
To ensure the vegetables are fully cooked before baking, each ingredient is sautéed first. The onions and garlic add aromatics, and the bell peppers add color and a slight crunch. I also use small peeled and diced Yukon gold potatoes that taste like mini hash browns for a sturdy yet creamy texture, although you can use any type of potato you like.
I use pre-cooked ham for the casserole. However, cooked breakfast sausage or bacon can be substituted. Cutting all the ingredients into smaller pieces before sautéing ensures even cooking and prevents denser elements from sinking to the bottom of the casserole.
Ingredients that help with texture
A ratio of 8 large eggs to 2 ½ cups of half and half ensures a velvety custard texture. If too many eggs are used, it can make the texture tough due to increased protein. Half and half adds a rich mouthfeel, without tasting gritty.
I use cornstarch to ensure a consistent custard-like texture throughout the casserole. It’s a nice bit of food insurance, even with the plethora of fillings threatening to break the texture of the egg base.
How long does it take to bake?
This egg breakfast casserole bakes in just 40 minutes! To check for doneness, use a toothpick inserted in the center of the pan. If it comes out dry, it’s ready. You can also gently jiggle the pan to see if the center moves. You want it to be firm.
For my science geeks, grab an instant-read thermometer and test the center of the casserole. Whole eggs start to solidify and set between 144 to 158°F (62 to 70°C). I found that between 180 to 190°F (82 to 88°C) yields the right finish, don’t overcook the casserole!
How to reheat breakfast casserole
The glory of making this dish is that you can make it ahead of time. The easiest way to reheat the breakfast casserole is to slice it into individual portions and microwave it for about 1 minute. I got 12 generous portions in a 9 x 13-inch pan. This is an excellent method if you’re meal-prepping for the week.
The entire pan can also be reheated in a 300°F (149°C) oven until the center is warm. Guess what? You can also make all the components, cover the tray with foil and refrigerate it overnight to bake it fresh the following day. A few more minutes may be required in the oven since all the ingredients are cold. This breakfast casserole will keep for up to 5 days once baked.
Other fillings to try
This easy breakfast casserole recipe has been a game-changer in our home. It makes a large serving to feed a crowd and can be wrapped up and eaten as a quick meal solution.
Next time, I plan on switching up the fillings with sautéed mushrooms, spinach, zucchini, sweet potatoes, butternut squash, sun-dried tomatoes, Parmesan cheese, mozzarella, or feta. Just keep the amounts of similar types of ingredients and the egg mixture the same.
More breakfast recipes
Recipe Science
Starch keeps the eggs smooth and creamy
Adding in a small amount of cornstarch keeps the consistency of the egg base tender and glossy. Cornstarch is a thickening agent that can also stabilize fully cooked eggs. The carbohydrates in the cornstarch prevent the proteins in the eggs from binding too tightly together. As the starches heat in the oven, it swells and thickens, creating a creamier mouthfeel.
Breakfast Casserole
Ingredients
- 2 tablespoons olive oil
- 1 ½ pounds Yukon gold potatoes, peeled, cut into ¼" cubes
- 1 cup red onion, ⅛" dice
- 1 tablespoon minced garlic
- 1 cup red bell pepper, ⅛" dice
- 10 ounces ham, ¼" dice
- 1 ½ teaspoon kosher salt, divided
- ¼ teaspoon black pepper
- ¼ cup sliced green onions
- 6 ounces sharp cheddar cheese, grated
- ¼ cup cornstarch
- 2 ½ cups half-and-half
- 8 large eggs
Instructions
- Preheat the Oven – Set the oven rack to the center position. Preheat to 350ºF (177ºC). Grease a 9×13-inch baking dish with olive oil on the bottom and sides.
- Saute the Potatoes – Heat a large pan or cast iron skillet over medium-high heat. Add 2 tablespoons olive oil. Once hot, add in the potatoes. Saute until tender, occasionally stirring, for 10 minutes.
- Saute the Mix-ins – Turn the heat down to medium. Add the onions and garlic, and saute for 1 minute. Add the bell peppers and saute for 2 minutes. Add the ham and saute for 1 minute. Turn off the heat and stir in ½ teaspoon salt, black pepper, and green onions.Transfer the mixture to the greased baking dish and spread it into an even layer. Evenly sprinkle half of the cheddar cheese on top.
- Add the Egg Base – In a large bowl, whisk together the cornstarch and 1 teaspoon salt. Add half-and-half and eggs, and whisk until thoroughly combined. Pour the egg mixture into the baking dish. Evenly sprinkle the remaining cheese on top.
- Bake the Casserole – Bake for 20 minutes. Rotate the pan and continue baking until the center sets and a toothpick inserted comes out clean, about 20 minutes. The internal temperature should be 180 to 190ºF (82 to 88ºC). Cool for 10 minutes before slicing and serving.
Recipe Video
Nutrition Facts
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.
David Witte says
I made this gor Mother’s Day Brunch and it was a hit. 5 Star Keeper. I will be making it again. Thank you Jessica!
Jessica Gavin says
Whoo-hoo! Thanks for sharing the breakfast casserole recipe for mother’s day!
Nancy J says
This was easy and delicious. I made a half recipe, just halving the ingredients. Worked well. Baking time was the same.
Jessica Gavin says
Thank you so much! I’m so happy that you were able to tailor the casserole recipe to your needs.
Teresa says
Could one use frozen potato cubes. I have some in the freezer that need to be used
Jessica Gavin says
You can defrost the potatoes, drain, saute, and add them to the breakfast casserole.
Cindy says
Is it possible to freeze this before it is baked so you can prepare ahead of time?
Jessica Gavin says
I think it would be better to bake, cool, and reheat. This works well for individual portions. That way, the ingredients in the casserole won’t sink to the bottom.
RJ Rodgers says
Can you freeze the Breakfast Casserole?
Jessica Gavin says
Yes, you can freeze the casserole. It would be easiest to freeze portioned-out pieces that are individually wrapped so that they can be defrosted easily.
Theodosia says
I love all your recipes and your directions! The breakfast casserole is amazing!
Jessica Gavin says
Thank you so much, Theodosia!
Michelle says
This is delicious. I saute a little baby spinach instead of ham, to make it vegetarian.
Jessica Gavin says
Thank you, Michelle! I love that you added spinach to make it vegetarian. Sauteing the vegetable is key for making the casserole not soggy, great job!
Donna says
This recipe looks delish. What do you think about cottage cheese as a substitute for half and half? (I dont’ have any half and half right now, but do have cottage cheese. Thanks.)
Jessica Gavin says
I think you could give cottage cheese a try, but it the texture of the casserole with be a lot more thick and firm with less moisture and extra protein. It will also be saltier, so I would remove some of the added salt in the recipe. Let me know how it goes!
linda mclain says
My breakfast casserole wont get firm
Jessica Gavin says
Have you checked to make sure that the oven’s temperature is correct? It may be too long? I would continue to bake until the center is firm.
maggie says
Jessica,
I am a loyal follower of your website…love your recipes! This casserole is one of my favorites. I use hash browns from the grocery freezer section when Im short on time. My family devours this casserole in no time! Thank you! 🙂
Jessica Gavin says
Hi Maggie! Thank you for your feedback, so smart to use hash browns as a quick substitution. Happy cooking!
Mandy says
Question….can i use flour instead of cornstarch?
Jessica Gavin says
No, I would not substitute flour for cornstarch, it might give the casserole a raw flour taste. I would omit it if you don’t have any.
Kate says
I’d like to try this but with only 4 eggs so how would I adjust the cornstarch ?
Jessica Gavin says
Add 2 tablespoons cornstarch for 4 eggs.
Mike says
Thank you for the great recipe! Adding the corn starch does noticably change the egg texture. I will try it with different ingredients next time-
Jessica Gavin says
Thank you for your feedback Mike!
Deb says
We had this for dinner last night. Instructions were straightforward and and ingredients readily available. Oh, and it was delish!
Leslie says
Hi Jessica!
Have you tried spinach in this recipe yet? If so, how much and how did it turn out?
P.S.
I love your recipes!
Jessica Gavin says
I would sautee about 3 to 4 cups of fresh spinach, I think it would taste amazing in the breakfast casserole.
Lisa says
My son is on “taper” for swimming. This means he is actually eating healthy breakfasts. I am hoping he can see the benefit of a healthy breakfast. This is the perfect recipe because it is both healthy and tasty. Thanks for sharing
Grace says
I am making this dish today. I have all the ingredients and…why not! Thanks for sharing.
Elizabeth A Mitchell says
Is there a nutritional reason that you peel the potatoes? I would rather use the bag of small Yukon Gold potatoes and just cube them. My sister in law fixed this for our Christmas Eve brunch. We LOVED it.
Jessica Gavin says
No, you can keep the peels on the potato.
Nina says
Hi there. Could I use plain milk vs half/half?
Jessica Gavin says
Yes, whole milk would work great.
Robert Owens says
Being diabetic, I have to watch my carb intake closely. Do you have any suggestions for a replacement for the potatoes in this recipe? This looks fantastic, but potatoes are one of the foods that my doctor has told me to avoid.
Thanks!
Jessica Gavin says
Perhaps some chopped cauliflower would be nice!
Virginia says
Love this! Thank you so much!
Darlene says
Hi Jessica- I made this recipe as written. Perfect. The second time I made it with leftover bits from the fridge keeping the ratio of ingredients to eggs as you suggested. Perfect. The cornstarch is truly the secret ingredient. I love science…and your recipes. Thank you for doing the research and testing. All I need to do is cook!
Desiree Rustulka says
Hi. Do you think this could be made the day before and cooked the next morning?
Jessica Gavin says
Yes, you can prep the recipe and then bake it the next day.
Sandy says
I want to make this for a large gathering that does not have an oven available. Could this be baked in a roaster? This looks so good, cant wait to try it!
Sandy says
Sorry Jessica I missed your first reply.
Yes the roaster can be set at 350. I would like to cook it in the roaster so I wont need to transfer it. I’m worried the texture will be soggy.
Jessica Gavin says
The texture shouldn’t be soggy of it’s cooked through, you may need more time until the egg sets in the center.
Sandy says
Would this work to make in a electric roaster or maybe transfer to a slow cooker to keep warm for a large gathering? There will not be an oven available. Love your detailed instructions and tips. Also the nutritional info is very helpful.
Jessica Gavin says
Hi Sandy- Can the electric roaster be set at 35- degrees? You can definitely keep it warm (slices) in the slow cooker.
Timothy Gist says
I made this for a big feed at work and it was a big hit! I made some minor substitutions … I replaced the ham with some fresh country sausage (I’m not really a ham guy – rinsed the fat off the sausage before adding it in according to the recipe) and I left out the salt (I’m on a low-sodium diet for my heart). I also used red, green and orange peppers to vary the colors in the finished product. I also dropped a spoonful of homemade salsa as a topping. At the end of the day I took home a clean pan!
I can see me making this again many times! I’m thinking of adding maybe 1/4 teaspoon of cumin to get a smokey, earthy flavor, and maybe a small amount of hot sauce to kick it up a notch!
I shared the recipe around the office!
Thanks for the inspiration!
mibs says
Hi Jessica, this is timely as I’ve been looking for a hearty breakfast/light dinner high protein dish. I’m wondering what I might be able to successfully substitute for the half and half. Do you have suggestions for those of us who are lactose intolerant?
Jessica Gavin says
Hi Mibs- I actually just saw some lactose free half-and-half that I used to make a recent batch. You could try that if you are comfortable. Other options could be almond, cashew or oat milk.
Kay Wakeham says
Hi Jessica,
This looks great. I had been thinking about something a I could prepare ahead of time so I could take to work instead of paying high dollars for an omelet in our cafe. I like the idea of switching it around from a kind of “Denver” casserole to an Italian, even Spanish one. I could see even wrapping it a corn or flour tortilla! I plan to try a version this weekend. I will let you know how it goes!
Jessica Gavin says
I’m totally with you on saving money at the work cafe, I made a tray for breakfast and it was a lifesaver and money saver! Let me know what flavors you come up with 🙂
Larry Vaught says
Hey Jessica,
I’m loving your recipes and the completeness of your instructions. One of the other things I REALLY like is that you include the nutritional information per serving. Many recipes do not have this.
Thanks so much!
Larry
Jessica Gavin says
You’re welcome Larry, I’m glad you’re finding the nutritional info helpful!
Jennie Johnson says
Looks Yummy Jessica!!
Thanks
Alison says
This looks amazing, Jessica, can’t wait to try it! Could I freeze individual portions? Thanks!
Jessica Gavin says
Hi Allison- It make be a little watery once you defrost and microwave, but if you are okay with that I would give it a try! It definitely holds up well in portions in the fridge from what I’ve tested and tasted.
Alison says
Thanks!
Karen Duffield says
I am very anxious to try this recipe. I have a breakfast casserole recipe with crescent roll dough which I would love to replace. My comment is that I freeze the individual squares of that recipe and then bake starting in a cold oven set at 350-375 for 20-25 minutes until warmed through. The dry method works very well and will be trying with this recipe. Not the convenience of a microwave but a little forethought yields great fresh baked results. Thanks for great recipes and tips.
Jessica Gavin says
Thank you for sharing your reheating tips, Karen!
Emilie Tribich says
Hi, I’m on Weight Watchers and I’d like to know if I can substitute 0% yogurt for the cream. There is no fat 1/2 & 1/2 available but the amount
in the ingredients is too calorie prohibitive. Any other ideas?
Made your Baked Salmon and it was great! Thanks.
Jessica Gavin says
I think you could give the 0% fat plain yogurt a try, however it might not be as tender of an egg casserole since there is less fat. But I think it would still be tasty! Please let me know if you make the recipe and how it turns out.