Blackened Mahi Mahi tacos are a perfect weekday lunch or dinner– just in time for Taco Tuesday! Fill warm corn tortillas with tangy cabbage slaw, blackened Mahi Mahi, and a drizzle of avocado lime crema or chipotle lime sauce. The easy fish taco recipe is ready in less than an hour for a quick weeknight meal when you’re in a pinch!
What is Blackened Mahi Mahi?
Blackening is a Cajun cooking technique that flavors everything from vegetables and seafood to poultry and other meat. The blackening process imparts the Mahi Mahi fillets with a unique charred taste while keeping them moist and juicy inside– all that color means flavor and lots of it!.
Start by coating the Mahi Mahi fillets in melted butter and blackened seasoning before searing them in a smoking hot cast-iron skillet to create a smoky and herbaceous crust.
Key Ingredients
Blackened Mahi Mahi tacos are loaded with fresh ingredients and toppings for a healthy and complete meal. Here’s everything you need to get started.
- Mahi Mahi: Mahi Mahi is a naturally sweet fish with mild flavor and pairs perfectly with bold blackened seasoning. While fresh Mahi Mahi is ideal, frozen fillets work and are more accessible—I typically use the frozen wild-caught Mahi-Mahi fillets from Costco.
Should I use fresh or frozen fillets?
Having lived in landlocked states my entire life (until now), I’ve developed a deep appreciation for frozen fish—Mahi Mahi being one of my favorites. The key to using frozen fish is setting aside the time to thaw the fish properly. The safest way to defrost Mahi Mahi is to move it from the freezer to the fridge and let it defrost overnight.
If you’re in a hurry, place the frozen fillets in a sealed bag (Costco fillets have individual wrappers) and add them to a mixing bowl with cold water for about 10-15 minutes, replacing the water as needed.
- Butter: Bind the blackening spices to the fish with unsalted butter for the best flavor.
- Blackened Seasoning: Make a flavorful blackened seasoning blend using chili powder, smoked paprika, garlic powder, dried oregano, kosher salt, ground cumin, coarse black pepper, and cayenne pepper for a little kick. Use store-bought blackened seasoning such as Blackened Redfish Magic Seasoning or Zatarain’s Blackened Seasoning if you are short on time.
- Oil: Use oil with a high smoke point to sear the fish.
- Cabbage Slaw: Toss shredded purple cabbage, green cabbage, or a mix of both with fresh cilantro leaves and lime juice to make a crunchy slaw for the tacos. For additional flavor, try this tangy homemade coleslaw with mint and cilantro.
- Avocado Lime Crema: Mix avocados, cilantro, fresh garlic cloves, Greek yogurt, lime juice, kosher salt, and black pepper in a food processor or blender to make creamy avocado lime crema to top the tacos.
- Corn Tortillas: Warm corn tortillas are the best way to enjoy blackened Mahi Mahi tacos, so be sure to check out these tips for how to heat corn tortillas. You can also use flour tortillas or lettuce wraps to wrap the tacos.
Additions and Substitutions
- Replace the seasoning. Coat the fish with flavorful Cajun seasoning mix like my copycat Slap Ya Mama Seasoning recipe instead of blackening seasoning.
- Swap the sauce. Replace avocado crema with a spicier sauce—serrano crema, chipotle lime sauce, cilantro lime crema, or Caribbean hot sauce. For a tasty variation, garnish the tacos with BBQ aioli, guacamole, pico de gallo, chunky salsa, pineapple corn salsa, and mango pico de gallo.
- Experiment with different types of fish. Use this recipe as a starting point to blacken a different type of fish, such as fresh halibut, sea bass, swordfish, or salmon. However, you may need to increase the cooking time if you choose a fish with a naturally thicker fillet.
Tools You’ll Need
Use a preheated cast-iron skillet or a large stainless steel skillet to create a nonstick coating for the best results. Heavy-bottomed pans work best for even heat distribution to give the fish a perfect blackened sear.
How to Make Blackened Mahi Mahi Tacos
The full recipe with measurements is in the recipe card below.
Step 1: Sprinkle kosher salt over the Mahi Mahi fillets and let them sit at room temperature for 5 minutes. Pat them dry with a paper towel to remove excess moisture.
Step 2: Combine the spices for the blackened seasoning in a small bowl. Then, brush the fillets with melted butter.
Step 3: Generously coat them on both sides with the seasoning.
Step 4: Warm oil in a preheated cast-iron skillet over medium-high heat until shimmering. Working in batches, carefully add 1-2 fillets to the pan away from you. Cook for 3-4 minutes on each side.
Step 5: Repeat with the remaining fillets, heating the pan in between batches.
Cooking Tip
Cooking times may vary depending on the thickness of the fillets. Use a food thermometer to know when the fish is done cooking.
Step 6: Set the fish on a cutting board to rest for 5-10 minutes. Meanwhile, warm the corn tortillas and prepare the cabbage slaw and avocado lime crema. Cut Mahi Mahi into bite-size pieces and build your tacos.
Expert Tips
- Use a hot skillet. The key to well-seared fish is a seasoned, smoking-hot pan. Heat a cast-iron skillet before adding the oil and cooking the fish.
- Pat dry the fish. Pat the fillets with a clean towel or paper towels to remove any excess moisture before you apply the butter spices to encourage a good sear.
- Carefully add the fish. Gently place the fish into the pan away from you to avoid splashing hot oil.
- How do you know when to flip the fish? When the filet releases from the bottom of 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 lean, meaning it is easy to overcook and will dry out if it cooks too long. The best (and most accurate) way to know when the fish is ready is to insert a meat thermometer into the thickest part of the fillet. According to the USDA, the safe internal temperature for Mahi Mahi is 145°F (63°C).
- Prepare for chaos. Okay, it’s not that bad, but 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.
If you enjoy the Mahi Mahi fish tacos, try more seafood recipes from Jamil Ghar!
What to Serve with Blackened Mahi Mahi Tacos?
The flaky fish is the best filling for burritos, rice bowls, salad, and tacos– of course! Serve them with your favorite taco toppings and sides. The seasoned fish tastes delicious with grilled pineapple, black beans, rice pilaf, avocado cucumber tomato salad, sautéed veggies, or air-fried plantains.
Topping Suggestions:
- Sour Cream
- Chopped Red Onion
- Pickled Jalapeños
- Lime Wedges
- Pickled Red Onion
What To Do With Leftovers
- Refrigerate: Store the blackened Mahi Mahi tacos’ fish, slaw, and sauce in separate airtight containers. Leftover mahi mahi will stay fresh 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 to prevent freezer burn.
- Thaw: Defrost the fish in the refrigerator overnight.
- Reheat: Line the blackened fish onto a rimmed baking sheet and cook at 275°F (135°C) for 15 minutes.
- Repurpose:Use the leftover blackened Mahi Mahi to make more tacos or use it top salads and burrito bowls with fresh ingredients like mango salsa, pico de gallo, or serrano crema.
Frequently Asked Questions
What does blackened Mahi Mahi taste like?
When seasoned with bold spices like blackened seasoning, the naturally mild fish develops a smoky and spicy coating from the cooking process for the best blackened Mahi Mahi tacos.
More Taco Recipes:
Blackened Mahi Mahi Tacos
- Small Bowl
- kosher salt
- 4 Mahi Mahi fillets
- 1 tablespoon unsalted butter, melted
- 2 tablespoons oil
- 3 tablespoons blackening seasoning
- 1½ tablespoons red chili powder
- 1 tablespoon garlic powder
- 1 tablespoon onion powder
- 1 tablespoon dried oregano
- 1½ tablespoons smoked paprika
- 2 teaspoons kosher salt
- 1½ teaspoons ground cumin
- 1 teaspoon coarse black pepper
- 1 teaspoon cayenne pepper
- ¼ head of cabbage, thinly shredded
- ¼ cup cilantro leaves, finely chopped
- lime juice, one lime
- 2 avocados, pitted and peeled
- ¼ cup cilantro leaves
- 2 garlic cloves, crushed
- ½ cup Greek yogurt
- lime juice, 1½ limes
- kosher salt,
- black pepper,
- 2-4 tablespoons warm water, to adjust the consistency
- 8 corn tortillas
- Sprinkle kosher salt over the Mahi Mahi fillets and let them sit at room temperature for 5 minutes. Pat them dry with a paper towel to remove excess moisture.
- Combine the spices for the blackened seasoning in a small bowl. Then, brush the fillets with melted butter and generously coat them on both sides with the seasoning.
- Warm oil in a preheated cast-iron skillet over medium-high heat until shimmering. Working in batches, carefully add 1-2 fillets to the pan away from you. Cook for 3-4 minutes on each side. Repeat with the remaining fillets, heating the pan in between batches.Tip: Cooking times may vary depending on the thickness of the fillets. Use a food thermometer to know when the fish is done cooking.
- Set the fish on a cutting board to rest for 5-10 minutes. Meanwhile, warm the corn tortillas and prepare the cabbage slaw and avocado lime crema. Cut Mahi Mahi into bite-size pieces and build your tacos.
- Use a hot skillet. The key to well-seared fish is a seasoned, smoking-hot pan. Heat a cast-iron skillet before adding the oil and cooking the fish.
- Pat dry the fish. Pat the fillets with a clean towel or paper towels to remove any excess moisture before you apply the butter spices to encourage a good sear.
- Carefully add the fish. Gently place the fish into the pan away from you to avoid splashing hot oil.
- How do you know when to flip the fish? When the filet releases from the bottom of 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 lean, meaning it is easy to overcook and will dry out if it cooks too long. The best (and most accurate) way to know when the fish is ready is to insert a meat thermometer into the thickest part of the fillet. According to the USDA, the safe internal temperature for Mahi Mahi is 145°F (63°C).
- Prepare for chaos. Okay, it’s not that bad, but 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.