Thaw fish if frozen. Remove skin from the fish. In a separate bowl, combine lemon juice, garlic salt, coriander and pepper sauce. Place fish in a shallow glass pan. Cover with marinade. Refrigerate for 1 hour or overnight. Lift the fish out of the marinade and roll the fillet securing it with a toothpick or wooden pick. Place in a well-greased 12x8 inch baking dish. Pour remaining mariande over fish. Drizzle melted margarine over the fish. Bake at 425 15-20 minutes until fish flakes easily. Serves