Place each piece of fish onto a piece of foil larger than the fish, pleat ends of foil to partially enclose fish.
Divide butter between fish, pour juice over fish; grind a little black pepper overfish.
Pleat foil firmly over fish to enclose completely.
Place onto oven tray, bake in moderate oven for about 25 minutes or until fish flakes easily when tested with a fork.
Unwrap partially to serve.