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Blackened Mahi Mahi Tacos

Blackened mahi mahi tacos are the perfect weekday lunch or Taco Tuesday dinner. The seasoned blackened mahi-mahi combines with cabbage slaw and avocado lime crema in a warm tortilla for flavorful and delicious tacos.

Blackened mahi mahi tacos on a plate.

Why You’ll Love This Recipe

  • Blackened mahi mahi tacos feature fresh ingredients for a complete and healthy meal.
  • The flaky white fish is the best filling for burritos, tacos, rice bowls, and taco salad – perfect for meal prep.
  • The fish taco recipe is ready in less than an hour for a quick dinner idea when you’re in a pinch!

What is Blackened Mahi Mahi?

Mahi-mahi is a healthy fish packed with protein and nutrients. I coat the fillets in butter and blackened seasoning before searing them in a hot cast-iron skillet to create a tasty crust that’s smoky and herbaceous.

Blackening is a Cajun cooking technique for vegetables, fish, poultry, and meat. The blackening process gives mahi-mahi a unique charred flavor while keeping it moist and succulent inside – all that color is flavor and lots of it!

Ingredients You’ll Need

  • Mahi-Mahi: Mahi-mahi is a naturally sweet and mild fish and pairs perfectly with the bold flavor of blackened seasoning. While fresh mahi-mahi is ideal, frozen fillets work. Thaw the fillets and pat them dry before using in this recipe. I use the frozen wild-caught mahi-mahi fillets from Costco
  • Butter: Butter binds the blackened seasoning to the fish filet.
  • Blackened Seasoning: Take a moment to check out my homemade blackened seasoning mix. It combines chili powder, garlic powder, onion powder, dried oregano, smoked paprika, ground cumin, salt, black pepper, and cayenne pepper for a bit of heat. If spice is an issue for you, skip the cayenne.
  • Cabbage Slaw: Create a crunchy slaw filling for the tacos using purple cabbage, green cabbage or a combination of the two tossed with fresh cilantro and lime juice.
  • Avocado Lime Crema: Process the avocados, cilantro, fresh garlic, Greek yogurt, lime juice, and salt and pepper in a food processor or blender to make the creamy sauce
  • Corn Tortillas: Warm corn tortillas are the best way to enjoy blackened Mahi Mahi tacos. Check out these tips and tricks for how to heat corn tortillas. You can also use flour tortillas or lettuce wraps if you prefer.

Should I Use Fresh or Frozen Fillets?

I’ve lived in landlocked states my whole life, so I am a big fan of frozen fish, especially mahi-mahi. The key to using frozen fish for this recipe is setting aside time for the fish to thaw properly. The best way to defrost mahi-mahi is to transfer it from the freezer to the fridge and leave it there overnight.

If you’re in a hurry, add frozen fillets to a sealed bag (Costco fillets have individual wrappers) and add them to a mixing bowl with cold water for about 10-15 minutes. If you have access to fresh fish, go for it!

Additions and Substitutions

Tools Used to Make this Recipe

For the best results, use a well-heated cast-iron skillet. You can use a large nonstick skillet or a stainless steel saute pan, but preheat it beforehand to create a nonstick coating. However, it’s important to note that when I have prepared the fish in pans other than cast iron, the blackened crust doesn’t form quite as well. 

How to Make Blackened Mahi Mahi Tacos

The full recipe with measurements is in the recipe card below.

Step 1: Salt the defrosted Mahi Mahi fillets and let them sit at room temperature for 5 minutes.

Pat them dry with a towel or paper towels to remove excess moisture.

Salted mahi mahi fillets.

Step 2: Brush the fillets with melted butter using a pastry brush. 

Butter brushed onto fillets.

Step 3: Then, combine the spice mix for the blackened seasoning in a small bowl and generously coat both sides of the fish with the seasoning.

Mahi mahi coated in blackened seasoning.

Step 4: Warm the oil in a cast-iron skillet over medium heat. Heat until it begins to smoke.

Once heated, carefully add 1-2 fillets to the pan to cook for 3-4 minutes on each side.

Mahi-mahi cooking in a pan.

Step 5: Repeat with the remaining fillets, heating the pan in between batches.

Tip: Cooking time may vary depending on the thickness of the filet. 

Mahi-mahi cooking in a pan.

Step 6: Set them aside to rest for 10 minutes, then slice the fish into smaller pieces.

Meanwhile, prepare the ingredients for the cabbage slaw, avocado lime crema, and warm the corn tortillas.

Pureed avocado lime crema in a blender.
Blackened mahi mahi tacos on a plate.

Expert Tips

  • The key to well-seared fish is a seasoned, smoking-hot skillet. Warm a large cast-iron skillet over medium to medium-high heat (depending on your range) and give it time to heat up before adding the oil and cooking the fish. Another necessary step is patting the fish dry with a paper towel to remove excess moisture before applying the butter and seasoning to encourage a good sear. 
  • Gently place the fish into the pan away from you to avoid splashing hot oil on yourself.
  • When the fish fillet releases from the pan, it’s ready to flip. If you notice it sticking, let it cook for longer before flipping.  
  • How do you know when the fish is done cooking? Mahi Mahi is versatile and easy to cook, but it’s a lean fish, meaning it’s easy to overcook and dries out if you cook it for too long. The best way to know when the fish is done is to insert a meat thermometer into the thickest part of the fish fillet; the safe internal temperature for Mahi Mahi is 145°F (63°C).
  • There will be a lot of smoke and sputtering, so do yourself a favor. Put on an apron and turn on the exhaust fan ahead of time.  
Blackened mahi mahi tacos on a plate.

What to Serve with Blackened Mahi Mahi Tacos?

What to do with the Leftovers

  • Refrigerate: Store the ingredients for the blackened Mahi Mahi tacos in separate airtight containers for 1-2 days.
  • Freeze: Cooked fish freezes for 4-6 months. Wrap the fillets in plastic wrap and place them in a freezer-safe bag or container.
  • Thaw: Defrost the fish in the refrigerator overnight.
  • Reheat: Line the fillets onto a rimmed baking sheet and cook in a preheated oven to 275°F (135°C) for 15 minutes.
  • Repurpose: You can serve leftover blackened mahi-mahi with fresh mango salsa. Top the fish with pico de gallo or serrano crema. Serve it with pilaf or rice and black beans for a fun spin on a burrito bowl.

Frequently Asked Questions

What does blackened mahi mahi taste like?

When seasoned with a spice blend like blackened seasoning, the naturally mild fish develops a thin crust with a kick of spicy flavor and a smoky richness from the cooking process to make the best blackened Mahi Mahi tacos.

More Taco Recipes:

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Blackened mahi mahi tacos on a plate.

Blackened Mahi Mahi Tacos

Tressa Jamil
Blackened mahi mahi tacos are a perfect weekday lunch or dinner. Fill warm corn tortillas with homemade slaw, seasoned fish, and avocado crema.
5 from 2 votes
Prep Time 20 minutes
Cook Time 25 minutes
Total Time 45 minutes
Course Dinner, Lunch, Main Course
Cuisine American
Servings 8 Servings
Calories 269 kcal
Ingredients
  
For the Blackened Seasoning:
  • tablespoons chili powder
  • 1 tablespoon garlic powder
  • 1 tablespoon onion powder
  • 1 tablespoon dried oregano
  • tablespoons smoked paprika
  • 2 teaspoons kosher salt
  • teaspoons ground cumin
  • 1 teaspoon black pepper, coarse ground
  • 1 teaspoon cayenne pepper
For the Mahi-Mahi:
  • 4 Mahi Mahi fillets
  • 1 tablespoon melted butter
  • 2 tablespoons oil
  • 3 tablespoons blackening seasoning
For the Cabbage Slaw:
  • ¼ head of cabbage, thinly shredded (purple or green)
  • ¼ cup fresh cilantro, chopped
  • lime juice, 1 lime
For the Avocado Lime Crema:
  • 2 avocados, pitted and peeled
  • ¼ cup fresh cilantro, chopped
  • 2 garlic cloves, crushed
  • ½ cup Greek yogurt, full-fat
  • lime juice, 1½ limes
  • kosher salt, to taste
  • black pepper, to taste
  • 2-4 tablespoons warm water, depending on your preferred consistency
Instructions
 
  • Salt the defrosted Mahi Mahi fillets and let them sit at room temperature for 5 minutes. Pat them dry with a towel or paper towels to remove excess moisture.
  • Brush the fillets with melted butter using a pastry brush. Then, combine the spice mix for the blackened seasoning in a small bowl and generously coat both sides of the fish with the seasoning.
  • Warm the oil in a cast-iron skillet over medium heat. Heat until it begins to smoke. Once heated, carefully add 1-2 fillets to the pan to cook for 3-4 minutes on each side.
    Tip: The cooking time may vary depending on the thickness of the filet. 
  • Set them aside to rest for 10 minutes, then slice the fish into smaller pieces. Meanwhile, prepare the ingredients for the cabbage slaw and avocado lime crema, and warm the corn tortillas.
Notes
Expert Tips:
  • The key to well-seared fish is a seasoned, smoking-hot skillet. Warm a large cast-iron skillet over medium to medium-high heat (depending on your range) and give it time to heat up before adding the oil and cooking the fish. Another necessary step is patting the fish dry with a paper towel to remove excess moisture before applying the butter and seasoning to encourage a good sear. 
  • Gently place the fish into the pan away from you to avoid splashing hot oil on yourself.
  • When the fish fillet releases from the pan, it’s ready to flip. If you notice it sticking, let it cook for longer before flipping.  
  • How do you know when the fish is done cooking? Mahi Mahi is versatile and easy to cook, but it’s a lean fish, meaning it’s easy to overcook and dries out if you cook it for too long. The best way to know when the fish is done is to insert a meat thermometer into the thickest part of the fish fillet; the safe internal temperature for Mahi Mahi is 145°F (63°C).
  • There will be a lot of smoke and sputtering, so do yourself a favor. Put on an apron and turn on the exhaust fan ahead of time.  
Nutrition Disclosure:
  • The nutritional information shown is an estimate provided by an online nutrition calculator. It should not be considered a substitute for professional advice.
Nutrition
Serving: 1 Serving | Calories: 269 kcal | Carbohydrates: 18 g | Protein: 20 g | Fat: 14 g | Saturated Fat: 3 g | Polyunsaturated Fat: 2 g | Monounsaturated Fat: 8 g | Cholesterol: 66 mg | Sodium: 511 mg | Potassium: 720 mg | Fiber: 6 g | Sugar: 2 g | Vitamin A: 366 IU | Vitamin C: 16 mg | Calcium: 68 mg | Iron: 2 mg
Did you make this recipe? Let me know how it turned out for you! Leave a comment below and follow @thejamilghar or tag #thejamilghar on Instagram!
5 from 2 votes (2 ratings without comment)
Recipe Rating