Blackened Fish Tacos with Avocado Lime Sauce

4.96 from 305 votes
↓ Jump to Recipe 92

This post may contain affiliate links | disclosure policy

A super simple blackened fish taco recipe served with a creamy avocado lime sauce to drizzle on top. Firm white fish is coated with a spicy seasoning blend and pan-fried until lightly charred on the surface for maximum flavor.

Two blackened fish tacos on plate

This fish taco recipe is inspired by a food adventure just south of the border in Baja California, Mexico. My husband and I stopped at several small seaside villages like Puerto Nuevo for langosta (lobster) and pescado (fish). The food in Baja is incredible. Street cart vendors selling elotes and tacos al pastor, carnitas, carne asada, lengua, and most restaurants have whatever your heart desires.

This recipe uses a Mexican-inspired spice blend that works with any type of fresh fish. This time I choose to Mahi Mahi for its lean flakey texture, which is a match made in heaven rolled up in a corn tortilla and all the taco fixings. Taco Tuesday is never going to the be the same from here on out!

person adding spices to fish fillets laid out on a sheet pan

Ingredients for the blackening seasoning

The best blackening season combines smoked paprika, brown sugar, garlic, onion, cumin, chili powder, salt, and black pepper. It layers on a flavor explosion that takes a mild white fish to bold and rustic in taste.

If you want more heat, just add more chili pepper, or better yet, some cayenne pepper. If you’re following a Paleo or Whole30 diet, you can omit the brown sugar. The sweetness is there to balance the savory seasonings and helps to brown the surface more quickly.

fish fillets cooking in a cast iron skillet

Mahi Mahi only requires a few minutes to cook before it gets dried out, so keep an eye on it. Start with a nice hot pan by pre-heating over medium-high heat for a few minutes until you can feel the heat rising. I use a cast iron skillet, however, stainless steel or nonstick pan will work too.

Press the fish against the pan

Add enough oil to coat the bottom of the pan, and then heat until almost smoking. Carefully add the fish and gently press on the fillet with a spatula for a few seconds so the flesh can make direct contact with the hot pan.

This also helps release some of the moisture from the surface of the fish so the meat can brown evenly. Flip the fish and finish cooking. This process takes about 5 to 6 minutes max.

Fish tacos on a plate with shredded lettuce and sliced tomatoes on top

Avocado lime sauce

A quick avocado lime sauce can be made using a blender to create a smooth and creaming topping. It’s a simple combination of sour cream, ripe avocado, cilantro leaves, fresh lime juice and zest, and serrano peppers.

Crema or plain Greek yogurt can be substituted for the sour cream. Any type of pepper can be used, just adjust the amount to your heat tolerance, this sauce is mild. The fresh, tart and creamy sauce cool down the spices on the fish for a tasty pairing.

Additional toppings

close up of a fish fillet on top of a tortilla with sauce

More Mexican recipes

Why do you add brown sugar to the seasoning?

The sugar not only adds a sweet molasses flavor but also speeds up browning on the surface of the mahi mahi. The desirable brown pigments appear at around 200°F (93°C) when the fructose in the brown sugar caramelizes to create a beautiful quick crust.

Blackened Fish Tacos with Avocado Lime Sauce

A super simple and flavorful recipe for blackened mahi mahi fish tacos that you won't need to head to Mexico to enjoy!
4.96 from 305 votes
Prep Time20 minutes
Cook Time10 minutes
Total Time30 minutes
Servings 8 tacos
Course Entree
Cuisine Mexican


Avocado Lime Sauce

  • ½ cup sour cream
  • ¼ cup water
  • 1 avocado, medium-sized and ripe
  • ¼ cup cilantro leaves, loosely packed
  • 2 tablespoons lime juice, fresh
  • ½ teaspoon lime zest, about 1 lime
  • ½ teaspoon minced serrano pepper, seeded

Fish Tacos

  • 1 ½ teaspoons smoked paprika
  • 1 ½ teaspoons dark brown sugar
  • ½ teaspoon garlic powder
  • ½ teaspoon onion powder
  • ½ teaspoon kosher salt
  • ¾ teaspoon cumin
  • ¼ teaspoon chili powder
  • ¼ teaspoon black pepper
  • 1 ½ pounds Mahi Mahi filets, cut lengthwise into smaller pieces if needed
  • 1 tablespoon vegetable oil
  • 8 corn tortillas, 6-inch
  • 8 lime wedges
  • 1 cup tomatoes, diced
  • 1 cup red cabbage, sliced thin
  • 1 cup green cabbage, sliced thin
  • cilantro, for garnish


  • Add sour cream, water, avocado, cilantro, lime juice, lime zest, and serrano pepper into a blender.
  • Process until smooth, scraping down the sides as needed. Add more water as needed to achieve desired consistency. Transfer to a small bowl and refrigerate.
  • Combine paprika, brown sugar, garlic powder, onion powder, salt, cumin, chili pepper and black pepper in a small bowl.
  • Sprinkle seasoning evenly over both sides of the fish filets.
  • Heat oil in a large cast-iron skillet or sauté pan over medium-high heat.
  • Add fish to pan then cook 2 to 3 minutes on each side or until the desired degree of doneness. The surface will blacken in color quickly so keep a close eye on the fish. 
  • Warm tortillas according to package directions.
  • Divide fish evenly among tortillas.
  • Serve with lime wedges, tomatoes, cabbage, and cilantro.

Recipe Video

YouTube video


  • Spice blend makes: 2 tablespoons plus 1 teaspoon.

Nutrition Facts

Serves: 8 tacos
Calories 172kcal (9%)Carbohydrates 15g (5%)Protein 18g (36%)Fat 5g (8%)Saturated Fat 1g (5%)Polyunsaturated Fat 1gMonounsaturated Fat 1gCholesterol 65mg (22%)Sodium 146mg (6%)Potassium 481mg (14%)Fiber 3g (12%)Sugar 4g (4%)Vitamin A 1350IU (27%)Vitamin C 19mg (23%)Calcium 60mg (6%)Iron 2mg (11%)

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.

Tried this recipe?

Tag me on Instagram. I'd love to see how it turns out!

Tag @jessica_gavin

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.

Quick & Easy Meals in Under 30 Minutes!
Get 25 simple meals your whole family will love.
Jessica Gavin standing in the kitchen

You May Also Like

Reader Interactions

Leave a Comment

Your email address will not be published. Required fields are marked *

Recipe Rating

92 Comments Leave a comment or review

  1. Sophia Wilkins says

    Hi there! My mom made these tacos tonight and they were absolutely amazing. We have more Mahi Mahi in the freezer so we were thinking about making them again. I was wondering if there’s anyway to freeze or save the cilantro avocado sauce so we could use it again. Emphasis on the freeze. Thank you for sharing this incredible recipe with us! Hope to hear from you soon!

  2. Rachel says

    Hi! I need to premake these before a dinner I’m going for.
    Do these reheat well? I would be reheating them there. Also how would I reheat them?

  3. Colleen Hageman says

    Absolutely love this recipe! I have made it multiple times and have shared it plenty too. Very quick and easy it is to make – yet very flavorful and delicious. This has definitely become one of my go-to recipes! Thank you!!

  4. Brian Fox says

    Quick Question: I haven’t made this yet, but I’m going to try this recipe as it looks fantastic. What would you substitute for Cilantro? My wife has a negative reaction to tasting cilantro like some people. Would you suggest parsley, mint, something else, or just leave it out?
    Thanks! Love this site and your book!

  5. Valerie C. says

    My family has requested these fish tacos multiple times over the last 4 months since I first made it. My son in law was skeptical at first but absolutely LOVED them, especially when I had a little extra blackening seasoning left and decided to do blackened shrimp to go with the fish. My daughter and I are making them again tonight (2nd time this week!). Thank you for such a wonderful recipe Jessica!

See More Comments