The Best Blackened Fish Sandwich Recipe (With Mango Slaw)

If you are looking for an explosion of bold flavor, texture, and color, this Blackened Fish Sandwich is the ultimate crowd-pleaser.

Featuring perfectly seasoned, smoky, and spicy fish fillets nestled inside a toasted brioche bun, this sandwich strikes a perfect balance. It is layered with a crisp, refreshing mango cabbage slaw and drizzled with a rich garlic herb aioli. It’s messy, vibrant, and takes less than 30 minutes to make!

Why This Easy Fish Sandwich Recipe Works

• The Perfect Balance: The intense heat from the blackened seasoning pairs beautifully with the sweet, tropical crunch of the mango slaw.

• Restaurant Quality at Home: Using fresh brioche buns and custom garnishes transforms simple fish fillets into a gourmet meal.

• Versatile Seafood Option: You can easily use mahi-mahi, cod, halibut, or salmon depending on what is fresh at your local market.

Ingredients For This Recipe

For the Blackened Fish:

• Fish Fillets: 2 large, thick white fish fillets (like mahi-mahi or cod)

• Blackened Seasoning: 2 tablespoons (smoked paprika, garlic powder, onion powder, cayenne pepper, oregano, thyme, salt, and black pepper)

• Butter: 2 tablespoons, melted (for coating the fish)

• Brioche Buns: 2 high-quality buns, split and toasted

For the Sweet Mango Slaw:

• Shredded Cabbage: 1 cup (mix of red and green cabbage)

• Fresh Mango: ½ cup, finely diced

• Cilantro: 2 tablespoons, chopped fine

• Lime Juice: 1 tablespoon, freshly squeezed

For the Creamy Herb Aioli:

• Mayonnaise: ⅓ cup

• Garlic: 1 clove, grated fine

• Fresh Parsley: 1 tablespoon, finely minced for that perfect green garnish

• Lemon Juice: 1 teaspoon

Step-by-Step Instructions

Step 1: Prepare the Mango Slaw and Aioli

In a medium bowl, combine the shredded cabbage, diced mango, cilantro, and lime juice. Toss well to combine and set aside in the refrigerator to allow the flavors to marry. In a separate small bowl, whisk together the mayonnaise, grated garlic, minced parsley, and lemon juice until smooth.

Step 2: Season the Fish Fillets

Pat your fish fillets completely dry with a paper towel. Brush both sides of the fish generously with melted butter, then coat them heavily with your blackened seasoning mix, pressing it into the flesh to ensure a thick crust.

Step 3: Sear to Caramelized Perfection

Heat a cast-iron skillet over medium-high heat until it begins to smoke slightly. Place the seasoned fish fillets into the hot pan. Sear undisturbed for 3 to 4 minutes per side. The spices should form a dark, deeply caramelized, and crispy crust.

Step 4: Assemble the Masterpiece

Spread a thin layer of the garlic aioli on the bottom of your toasted brioche buns. Pile a generous heap of the refreshing mango slaw on top. Carefully place the hot, crispy blackened fish fillet over the slaw. Top the fish with an extra spoonful of the creamy aioli and a final sneak of fresh parsley. Close the sandwich and serve immediately while hot!

Expert Cooking Tips

Tip #1: Use a Cast-Iron Skillet. To achieve an authentic, deeply caramelized crust, cast iron is essential for maintaining even, high heat.

Tip #2: Don’t Move the Fish. Let the fish sit undisturbed once it hits the pan to allow the spices to form a proper blackened sear without sticking.

Frequently Asked Questions (FAQs)

What is the best fish for a blackened fish sandwich?

Firm white fish varieties like mahi-mahi, grouper, cod, or snapper hold up best to the high heat and heavy seasoning required for this recipe.

Is blackened fish spicy?

It has a kick due to the cayenne pepper and paprika, but you can easily control the heat level by making your own seasoning blend and reducing the cayenne.