Preheat oven to 450 degrees F. 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 teaspoon salt; toss well. Bake at 450 degrees for 20 minutes or until browned and crisp, stirring after 10 minutes.
Drain fish, discard liquid. Sprinkle fish with 1/4 teaspoon salt. Lightly spoon flour into dry measuring cup, level with a knife. Combine remaining 3/4 cup beer , flour and 1/2 teaspoon freshly ground black pepper in a medium bowl. Add fish to beer mixture, tossing gently to coat. Heat remaining 3 tablespoons 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 teaspoon salt. Serve immediately with chips.