Preheat your oven to 200°F (95°C) to keep the fries warm after frying.

Place the cut potatoes in a large pot and cover with cold water. Bring to a boil and cook for 5 minutes. Drain and let them cool slightly.

In a large bowl, mix 3/4 cup of flour, baking powder, salt, pepper, and paprika (if using). Gradually whisk in the cold sparkling water until the batter is smooth.

Heat about 2 inches of vegetable oil in a large, deep skillet or pot over medium-high heat until it reaches 350°F (175°C).

While the oil is heating, pat the fish fillets dry with paper towels. Dredge each fillet in the remaining 1/4 cup of flour, shaking off any excess.

Dip the floured fish into the batter, ensuring it is fully coated.

Carefully place the battered fish into the hot oil, frying in batches to avoid overcrowding. Fry for about 4-5 minutes per side or until golden brown and cooked through. Remove and place on a paper towel-lined plate.

In the same oil, add the pre-cooked fries and fry until golden and crispy, about 3-4 minutes. Remove and drain on paper towels.

Keep the fried fish and fries warm in the oven while you finish frying the remaining batches.

Serve hot with tartar sauce, malt vinegar, or your favorite dipping sauce.