01 -
Cut the fillets into strips about 1 1/2 inches wide. Pat very dry with paper towels and season lightly with salt and pepper.
02 -
In a large bowl, whisk together the flour, cornstarch, baking powder, salt, paprika, and cayenne until evenly combined.
03 -
Pour in the ice-cold water and whisk until smooth. The batter should be thin, similar to heavy cream. Add a splash more water if it feels thick.
04 -
Pour 2 to 3 inches of oil into a heavy pot or Dutch oven and heat to 350°F. Use a candy thermometer to monitor the temperature.
05 -
Working in batches, dip fish strips into the batter and let excess drip off. Carefully lower into the hot oil and fry for 3 to 4 minutes, turning once, until deep golden brown.
06 -
Transfer cooked fish to a wire rack set over a baking sheet. Sprinkle lightly with salt while hot. Serve immediately with lemon wedges and tartar sauce.