Thaw fish, if frozen. Rinse fish and pat dry with paper towels. For marinade, in a small bowl combine mint, soy sauce, lime peel, lime juice, oil, and pepper. Place fish in a self-sealing plastic bag set in a shallow dish. Pour marinade over fish; seal bag. Turn bag to coat fish. Marinate in the refrigerator for 1 hour, turning bag occasionally.
Drain fish, discarding marinade. Measure thickness of fish. Place fish skin side down on unheated rack of broiler pan; tuck under any thin edges. Broil 4 inches from heat until fish flakes easily with a fork. (Allow 4 to 6 minutes per 1/2-inch thickness. If fish is 1 inch or more thick, turn it over halfway through broiling.) Serve with lime wedges. Makes 4 servings.