Chef Jake Thompson - Comfort Food Specialist
👨‍🍳 Seafood & Grill Expert

Recipe by Mitchell

🎓 Culinary Arts Graduate ⏰ 18+ Years Experience 🍽️ Coastal Cuisine Master

❤️ My Recipe Story

"Growing up near the coast, I always loved fresh fish sandwiches, but I felt they often lacked texture. By combining the spicy, charred crust of blackened mahi-mahi with the smoky crunch of a BLT, this recipe creates the ultimate surf-and-turf sandwich experience."

Jake specializes in elevated comfort food that brings bold flavors to classic dishes. He's spent years perfecting techniques that maximize flavor while maintaining the hearty, satisfying nature of traditional American cuisine.

View All Mitchell's Recipes →
Close up of blackened mahi-mahi sandwich with bacon, lettuce, and tomato on toasted bread

Choosing the Right Fish

For this sandwich, you need a firm white fish that can stand up to high heat without falling apart. Mahi-Mahi is the top choice because of its dense flakes and mild sweetness that balances the spicy blackening seasoning. Grouper or Snapper are excellent alternatives.

Ensure your fillets are approximately the same size as your bread slices. If the fillets are too thick, butterfly them gently so they cook evenly and are easier to eat as a sandwich.

💡 Professional Tip

Pat the fish completely dry before applying the spice rub. Moisture creates steam, which prevents that signature dark, flavorful crust from forming.

Frequently Asked Questions

It has a kick due to the blackening spice (which usually contains cayenne), but the cooling tartar sauce, fresh tomato, and bread balance the heat perfectly.

Yes, just make sure to thaw it completely in the refrigerator overnight and pat it very dry with paper towels to remove excess moisture before cooking.

A heavy-bottomed stainless steel pan or a non-stick pan works too, but cast iron gives the best sear and crust development for blackening.

Absolutely. Preheat your grill to high, oil the grates well, and cook the fish for 3-4 minutes per side. It adds a wonderful smoky flavor.

It's typically a blend of paprika, cayenne pepper, onion powder, garlic powder, black pepper, salt, oregano, and thyme.

Sourdough, Ciabatta, or a sturdy Brioche bun work best. You want bread that can hold the weight of the fish and sauce without getting soggy.

The fish should flake easily with a fork and be opaque all the way through. The internal temperature should reach 145°F (63°C).

Yes, use oil instead of butter for searing, and ensure your tartar sauce or mayo is dairy-free. The bread should also be checked for dairy ingredients.

Recipe Troubleshooting Guide

✅

Fish Falling Apart

Problem: Fillets break when flipping

Solution: Wait until the fish naturally releases from the pan before flipping. If it sticks, it needs another minute. Use a wide, thin spatula.

✅

Soggy Bread

Problem: Bottom slice gets wet quickly

Solution: Toast the bread well and place the lettuce on the bottom slice first to create a moisture barrier between the bread and the hot fish.

✅

Burnt Spices

Problem: Seasoning burns before fish cooks

Prevention: Turn the heat down slightly if using very thick fillets, or finish them in the oven at 350°F after searing the outside.

✅

Too Salty

Problem: Sandwich tastes overly salty

Recovery: Bacon and store-bought blackening mixes are salty. Use a low-sodium seasoning blend or omit extra salt on the fish.

✅

Chewy Bacon

Problem: Bacon pulls out of sandwich when biting

Prevention: Cook bacon until very crispy so it breaks easily, or chop the bacon into large pieces rather than leaving them as whole strips.

✅

Dry Fish

Too Sweet: Add a slice of pineapple or mango salsa

Too Salty: Add capers to the tartar sauce

Bland: Squeeze fresh lemon juice over the cooked fish before assembling

Fresh mahi-mahi fillets, blackening spices, thick bacon, tomatoes, lettuce, and sourdough bread on a prep table

Building the Perfect Stack

Assembly matters in a sandwich this substantial. Always toast your bread to provide structural integrity. Placing the lettuce on the bottom bun acts as a shield, preventing the juices from the hot fish from making the bread soggy immediately.

The sauce should go on both slices of bread—not just for flavor, but to help hold the toppings in place. The bacon should go on top of the fish so its texture stands out against the soft bread, rather than getting lost under the fish.

Essential Ingredient Notes

  • Mahi-Mahi: Look for firm, pinkish-white flesh with no strong fishy odor. Fresh is best, but flash-frozen vacuum-sealed fillets are excellent quality.
  • Tartar Sauce: Homemade is best! Mix mayo, chopped dill pickles, capers, lemon juice, and fresh dill. It cuts through the richness of the bacon.
  • Sourdough Bread: Use a rustic loaf and slice it thick (about 3/4 inch). The tang of sourdough complements the savory seafood perfectly.
Mahi-mahi fillets sizzling in a cast iron skillet with blackening spices creating a dark crust

The Blackening Technique

Blackening isn't about burning food; it's about browning the spices and butter solids to create a deep, savory crust. You need high heat and confidence. The kitchen might get a little smoky, so turn on your exhaust fan before you start.

Don't move the fish around. Place it in the hot pan and leave it alone. This contact time is what develops the 'blackened' crust. If you move it too soon, the spices will slough off and the fish won't crisp up.

Butter Basting

Add a knob of butter during the last minute of cooking and spoon it over the fish. This adds moisture and helps bloom the spices.

Ultimate Blackened Mahi-Mahi BLT Sandwich

Prep 15 min
Cook 10 min
Serves 4 servings
Level Easy

📋 Ingredients

Sandwich Components

  • 120ml tartar sauce
    Creamy element
  • 30g blackening seasoning
    For the signature crust
  • 30ml olive oil
    For searing
  • 30g butter
    For richness and basting
  • Lemon wedges
    For serving

Cooking Essentials

  • 4 mahi-mahi fillets (6oz each)
    Firm, white fish works best
  • 8 slices thick-cut bacon
    Cooked until crispy
  • 8 slices sourdough bread
    Toasted golden brown
  • 4 leaves green leaf lettuce
    For crunch and freshness
  • 2 large tomatoes
    Sliced thick

Instructions

  1. Cook the Bacon

    In a large skillet over medium heat, cook the bacon strips until crispy, about 6-8 minutes. Remove to a paper towel-lined plate to drain. Drain most of the fat from the pan, leaving a thin layer for the fish.

  2. Season the Fish

    Pat the mahi-mahi fillets dry with paper towels. Generously coat both sides of each fillet with the blackening seasoning, pressing it gently into the flesh.

  3. Sear the Fish

    Heat the skillet with the remaining bacon fat and olive oil over medium-high heat. Add butter. Once melted and frothy, add fish fillets. Cook for 3-4 minutes per side until blackened on the outside and opaque in the center.

  4. Toast Bread

    While the fish rests, toast the sourdough slices until golden brown. Spread a generous layer of tartar sauce on one side of each bread slice.

  5. Assemble

    Layer the bottom slice with lettuce and tomato slices. Place the hot blackened fish on top, followed by two strips of crispy bacon. Top with the second slice of bread, slice in half, and serve immediately.

Recipe Notes & Tips

Side Dishes

These sandwiches are great with coleslaw, sweet potato fries, or a simple cucumber salad.

Seasoning DIY

If you don't have store-bought blackening seasoning, mix 1 tbsp paprika, 1 tsp cayenne, 1 tsp onion powder, 1 tsp garlic powder, and salt/pepper.

Leftovers

Store fish and sandwich components separately. Reheat the fish in a skillet or air fryer to recrisp before assembling a new sandwich.