Preheat oven to 450 degrees. Combine fish and 1/4 cup beer in a medium bowl. Cover and chill for 1 hour.
Place potatoes on a jelly-roll pan coated with cooking spray. Drizzle with 1 tablespoon oil and sprinkle with 1/4 tsp. salt; toss well. Bake at 450 degrees for 20 minutes or until browned and crisp, stirring after 10 minutes.
Drain fish, discard liquid, and sprinkle fish with 1/4 tsp. salt. Lightly spoon flour into dry measuring cup, level with a knife. Combine remaining 3/4 cup beer, flour and 1/2 tsp. freshly ground black pepper in a medium bowl. Add fish to beer mixture, tossing gently to coat.
Heat remaining 3 tbsp. oil in a large nonstick skillet over medium-high heat. Remove fish from bowl, shaking off excess batter. Add fish to pan; cook 3 minutes or until browned. Turn fish over, cook 3 minutes or until done. Sprinkle fish with 1/4 tsp. salt. Serve immediately with chips.