Fresh Fish Sandwich Recipe

Prepare fish

Pat the fish fillets dry with paper towels. Cut into 4 sandwich-sized portions if necessary (about 4–5 oz each).

Season

In a small bowl combine kosher salt, black pepper, smoked paprika, garlic powder, and cayenne (if using). Brush both sides of fillets with 2 tbs olive oil, then rub the spice mixture evenly over both sides. Let rest 5–10 minutes at room temperature while you prepare other components.

Grill (recommended)

Preheat grill or grill pan to medium-high (about 400°F / 200°C). Oil the grate or pan lightly. Grill fillets skin-side down (if skin-on) for 3–5 minutes until grill marks form, then carefully flip and cook another 2–4 minutes until fish flakes easily and registers 135–140°F in the thickest part. Remove and rest 2 minutes.

Blackened (pan-sear)

Heat a heavy skillet (cast iron recommended) over high heat until smoking slightly. Add 1 tbs olive oil. Place fillets in pan and press gently for even contact. Cook 2–3 minutes until a dark crust forms, flip and cook 1–2 more minutes until cooked through (135–140°F).

Fried (crispy)

Set up dredge: whisk egg and buttermilk in a shallow bowl. Combine flour, cornstarch, cornmeal and a pinch of salt in another. Dip each seasoned fillet in the egg mixture, then coat in the flour mix, shaking off excess. Heat 1 cup vegetable oil in a skillet to 350°F (medium-high). Fry fillets 2–3 minutes per side until golden and cooked through. Transfer to a paper towel-lined plate to drain and lightly salt.

Make sauce

In a small bowl whisk together 1 cup mayonnaise, 2 tbs key lime juice, 1 tsp lime zest, 1 tsp honey, a pinch of salt and a pinch of black pepper until smooth. Taste and adjust lime or honey as needed. Chill until assembly.

Prep produce

While the fish cooks, slice tomato and thinly slice red onion. Tear or wash lettuce leaves and pat dry. If using pickled jalapeños or cilantro, have them ready.

Toast buns

Heat a skillet over medium-low heat and melt 2 tbs butter. Spread a thin layer of butter inside each brioche split and toast cut-side down in the pan until golden, about 1–2 minutes.

Assemble sandwiches

Spread about 1.5–2 tbs key lime mayo on the bottom half of each toasted brioche. Place a lettuce leaf on the mayo, then a hot fish fillet. Top each fillet with a slice of tomato, a few rings of red onion, and optional jalapeños and cilantro. Finish with another drizzle (or 1 tbs) of key lime mayo on the top bun and place bun over sandwich.

Serve sandwiches immediately with lime or lemon wedges on the side. Recommended sides: fries, coleslaw, or a light salad.