Blackened Fish Recipe

Prepare fish

Pat fish fillets dry with paper towels. Season both sides lightly with 1 tsp salt and 1 tsp black pepper; set aside.

Make blackening spice

In a small bowl combine paprika, garlic powder, onion powder, dried thyme, dried oregano, cayenne pepper and remaining pinch of salt and pepper (use the listed amounts from ingredients). Mix thoroughly.

Coat fish

Rub the blackening spice evenly onto both sides of each fillet, pressing gently so the spice adheres. Let sit 5 minutes to come closer to room temperature.

Sear fish

Heat a large cast-iron or heavy skillet over medium-high heat until very hot (2–3 minutes). Add 3 tbs vegetable oil and swirl to coat. Carefully add fillets (do not overcrowd; cook in two batches if needed). Sear 2–3 minutes without moving until a dark crust forms. Flip gently and cook 1.5–3 minutes more depending on thickness, until fish is opaque and flakes with a fork (internal temp ~135–140°F / 57–60°C).

Finish

If using, add 2 tbs brown butter to the pan and spoon over the fillets for 30–60 seconds to glaze. Transfer fish to a plate and tent with foil to keep warm while assembling sandwiches.

While fish rests, whisk together 1/2 cup mayonnaise, 1 tsp Dijon mustard, 1 tsp prepared horseradish, 1 tbs lemon juice, 1 tsp Worcestershire sauce, 1/2 tsp hot sauce, 1 tsp chopped capers, 1 tsp chopped cornichon/dill pickle, 1 tbsp minced parsley, 1/4 tsp salt and 1/4 tsp black pepper in a small bowl. Taste and adjust seasoning or acidity with additional lemon juice or salt if desired. Chill until ready to use.

Split brioche buns and lightly butter cut sides with the softened butter. Toast in a skillet or under broiler until golden and crisp, about 1–2 minutes per side on medium heat.

On the bottom bun place two leaves of lettuce, one or two tomato slices, and a few thin slices of red onion if using.

Prepare potatoes

Peel (optional) and cut russet potatoes into 1/3–1/2 inch sticks. Rinse under cold water until water runs clear to remove excess starch. Pat completely dry with towels.

Fry

Heat 100 ml vegetable oil in a heavy pot to 325°F (163°C) for a first fry. Fry potatoes in batches for 3–4 minutes until just tender but not browned. Remove and drain on paper towels. Increase oil temperature to 375°F (190°C). Return fries in batches and fry 2–3 minutes until golden and crisp. Drain on paper towels and immediately season with 1 tsp salt and 1/2 tsp black pepper.

Spread 1–2 tbs remoulade on the toasted top bun. Place the blackened fish fillet on the dressed bottom bun with lettuce and tomato. Close sandwich, press gently, and serve with a generous portion of hot french fries on the side. Serve additional remoulade alongside for dipping.