Fish Sandwich Recipe

Make the tartar sauce

Finely chop the dill pickle (if using whole) and parsley. In a small bowl combine mayonnaise, chopped pickle or relish, chopped capers, lemon juice, Dijon mustard, parsley, salt and pepper. Stir until smooth. Taste and adjust salt, pepper or lemon. Cover and refrigerate while you prepare the fish (can be made up to 2 days ahead).

Prep the fish

Pat cod fillets dry with paper towels. If thick, halve horizontally to an even thickness (~1 inch) for even frying. Season both sides with 1/2 tsp salt and 1/4 tsp black pepper and a light dusting of paprika and garlic powder.

Make the batter

In a bowl whisk together flour, cornstarch and baking powder with remaining 1/2 tsp salt and 1/4 tsp black pepper. In a separate small bowl beat the egg and add the cold sparkling water. Pour the wet into the dry and whisk briefly — batter should be slightly lumpy and coat the fish, not overly thick. If too thick, add 1-2 tbsp more cold water.

Heat the oil

Pour vegetable oil into a deep pot or heavy skillet to a depth of about 2 inches (enough to mostly submerge fillets). Heat oil to 350°F (175°C). If you don't have a thermometer, test by dropping a small bit of batter into oil — it should sizzle and rise steadily without burning.

Fry the fish

Dust each seasoned fillet lightly with flour (this helps batter stick), then dip into the batter to coat completely, letting excess drip off. Carefully lower fillets into hot oil, frying 1–2 pieces at a time to avoid crowding. Fry for 3–5 minutes per side depending on thickness, turning once, until golden brown and internal temperature reaches 145°F (fish flakes easily). Remove to a wire rack or paper towels to drain and rest for 1–2 minutes.

Prepare the buns and assembly

Lightly toast hoagie buns cut-side up in a toaster or under a broiler until just golden (about 1-2 minutes). Spread about 1 to 2 tablespoons of tartar sauce on each bottom bun. Place 2 lettuce leaves on each bottom bun, then set a hot fried cod fillet on top. Spoon an additional 1 tablespoon of tartar sauce over the fish if desired. Top with the bun crown. Serve immediately with lemon wedges on the side for squeezing over the fish.