In a heavy 3-quart saucepan or deep-fat fryer heat 2 inches of oil to 365 degree F.
Meanwhile, thaw fish, if frozen. Rinse fish and pat dry. In a large bowl stir together the flour, salt, and pepper. Sprinkle both sides of fish with 2 tablespoons of the flour mixture. Add beer to remaining flour mixture and stir until combined. Dip fish pieces, one at a time, in the batter, coating well. (Batter will be thick.)
Carefully lower the fish pieces into the hot oil. Fry 1 or 2 pieces at a time for 4 to 6 minutes or until golden and fish flakes easily when tested with a fork. Drain on paper towels and keep warm in a 300 degree F oven while frying remaining fish. Makes 4 servings.