Grammy Mary's Fried Fish Sandwich Recipe

Prepare fish

Pat the haddock fillets dry with paper towels. Season both sides with 1 teaspoon kosher salt, 1/2 teaspoon black pepper, and 1/4 teaspoon garlic powder. Let rest 5 minutes while you prepare the batter and oil.

Make batter

In a bowl whisk together 1 cup all-purpose flour, 1/4 cup cornstarch and 1 teaspoon baking powder. In a separate small bowl beat 1 large egg and then whisk into the dry ingredients with 1 cup cold sparkling water (or cold beer) until just combined; batter should be slightly thick but still runny. Do not overmix — a few small lumps are fine. Keep batter cold (set bowl over a larger bowl with ice if needed) until frying.

Heat oil

Pour about 4 cups vegetable oil into a deep sauté pan or Dutch oven to a depth of about 2 inches. Heat oil over medium-high heat to 350–360°F (175–180°C). If you don’t have a thermometer, test by dropping a spoonful of batter — it should sizzle and rise immediately without burning.

Fry fish

Working one or two fillets at a time (do not overcrowd), dust each seasoned fillet lightly with a tablespoon of flour, then dip into the batter to coat completely. Gently lower into the hot oil. Fry until batter is golden brown and fish registers 145°F (63°C) internally or flakes easily, about 4–6 minutes depending on thickness. Turn once midway if necessary. Transfer to a wire rack set over a baking sheet or to paper towels to drain briefly. Keep warm in a 200°F (95°C) oven if making multiple sandwiches.

Prepare potatoes

Wash and peel (optional) the russet potatoes. Cut into 1/4–1/2-inch sticks for classic fries. Rinse the cut potatoes under cold water until water runs clear to remove excess starch. Drain and pat completely dry with towels.

Fry potatoes (two-stage)

Heat 2 cups vegetable oil in a heavy-bottomed skillet or fryer to about 325°F (160°C). Fry potatoes in batches for 3–4 minutes until just soft but not browned. Remove and drain on paper towels. Increase oil temperature to 375°F (190°C). Fry the par-cooked fries in batches again for 2–3 minutes until golden and crisp. Drain on paper towels and immediately season with 1 teaspoon salt.

Prepare rolls and produce

Split the hoagie rolls lengthwise, leaving a hinge if desired. If you like, toast the cut sides lightly in a 400°F (200°C) oven for 3–4 minutes or on a hot griddle until just golden. Rinse and dry bib lettuce leaves and slice the tomato into 1/4-inch rounds.

Assemble sandwich

Spread about 2 tablespoons tartar sauce evenly on the bottom half of each hoagie roll. Place 2 lettuce leaves over the sauce, then arrange 2–3 tomato slices. Set a hot fried haddock fillet on top of the tomatoes. Spoon about 1/2 cup creamy coleslaw atop the fish (or on the side inside the roll if preferred). Add a squeeze of lemon over the fish and, if desired, a few drops of hot sauce. Close the roll and, if making to-go, wrap lightly to hold together.

Garnish & serve

Place the sandwich on a plate with a generous portion of fries. Sprinkle chopped parsley over fries or coleslaw if desired. Serve immediately with extra tartar sauce and lemon wedges on the side.

Offer hot sauce at the table for diners who want heat. Sprinkle chopped fresh parsley over the fries or the sandwich for color and brightness.