Fried Haddock Sandwich Recipe

Prepare fish

Pat the haddock fillets dry with paper towels and cut into sandwich-sized portions (about 4 pieces from 1 lb). Lightly season both sides with 1/2 teaspoon fine sea salt and 1/4 teaspoon freshly ground black pepper.

Make batter

In a medium bowl whisk together 1/2 cup all-purpose flour, 2 tablespoons cornstarch, and 1 teaspoon baking powder. Stir in 1 teaspoon fine sea salt and 1/2 teaspoon black pepper. In a separate bowl whisk the egg, then add 3/4 cup cold beer and whisk to combine. Pour the wet into the dry and gently whisk until mostly smooth — a few small lumps are fine. If the batter is too thick to coat, add up to 2 tablespoons cold sparkling water to adjust; consistency should be like heavy cream and able to coat the back of a spoon.

Dredge and fry

Pour vegetable oil into a deep skillet or heavy-bottomed pot to a depth of about 1.5 inches (use approximately 3–4 cups depending on pan). Heat to 350°F (175°C). Place the 1/2 cup flour for dredging on a plate. Lightly coat each seasoned haddock piece in the flour, shaking off excess, then dip into the beer batter to fully coat. Carefully lower battered fillets into the hot oil, frying 2–4 minutes per side depending on thickness, until golden brown and an instant-read thermometer reads 145°F (63°C) or the fish flakes easily. Do not overcrowd — fry in batches if needed. Transfer cooked fillets to a wire rack set over a sheet pan to drain and keep warm. Sprinkle with a pinch of salt immediately after frying.

While fish rests, combine 1/2 cup mayonnaise, 1 tablespoon finely diced dill pickle, 1 teaspoon chopped capers, 1 teaspoon fresh lemon juice, 1/2 teaspoon Dijon mustard, and 1 teaspoon chopped fresh dill or parsley in a small bowl. Season with 1/4 teaspoon salt and 1/8 teaspoon black pepper. Taste and adjust acidity or salt as desired. Refrigerate until assembly. (Makes about 1/2 cup.)

In a medium bowl toss together 2 cups thinly sliced red cabbage, 1/4 cup julienned green apple (optional), and 2 tablespoons thinly sliced red onion. In a small bowl whisk 1 tablespoon apple cider vinegar, 1 teaspoon olive oil, 1/2 teaspoon honey or maple syrup, 1/4 teaspoon fine sea salt and 1/8 teaspoon black pepper. Pour dressing over cabbage mixture and toss to coat. Let sit at room temperature for 10–15 minutes to soften slightly and marry flavors. Taste and adjust salt or vinegar if needed.

Lightly butter the cut sides of the 4 buns with the softened unsalted butter. Toast in a skillet over medium heat or in a 375°F (190°C) oven until golden and slightly crisp, about 1–2 minutes per side on the skillet or 4–6 minutes in oven.

To build each sandwich: spread about 1 tablespoon of tartar sauce on the bottom bun. Place one fried haddock fillet on top. Add about 1/2 cup loosely packed red cabbage slaw over the fish. Spoon another 1/2 tablespoon tartar sauce on the top bun (optional) and place on sandwich. Garnish with a squeeze of lemon and a sprinkle of chopped parsley or dill if using.

Serve immediately with extra lemon wedges and remaining tartar sauce on the side.