Preheat oven to 350° F.
Spray a shallow baking dish with vegetable cooking spray. Lay fish fillets in dish; skin side down. Mix butter and garlic together and brush liberally over fish. Season with salt and pepper. Layer green pepper, onion and tomatoes over fish. Drizzle evenly with lemon juice.
Bake for 20 minutes, or until fish flakes easily with a fork. Serve warm.Servings: 3