Heat gas grill for direct heat. Sprinkle both sides of fish steak with salt and pepper. Mix butter and lemon juice and set aside.
Grill fish steak uncovered about 4 inches from medium heat 7 to 10 minutes, brushing 2 or 3 times with butter mixture. Carefully turn fish. If fish sticks to the grill, loosen gently with a turner. Brush other side with butter mixture.
Grill uncovered 7 to 10 minutes longer or until fish flakes easily with fork. Brush with butter mixture.
Serve and enjoy.