ombine all marinade ingredients, mixing well to dissolve the salt. In a heavy-duty resealable plastic bag combine London broil with marinade. Seal bag, pressing out excess air. Marinate, chilled, turning occasionally, for 4 to 6 hours. Prepare grill. Remove steak from marinate, letting excess drip off, and grill on an oiled rack set 5 or 6 inches over glowing coals, for 7 to 9 minutes on each side for medium rare. Transfer steak to a cutting board, cover with foil, and let stand 10 minutes before carving. Cut across the grain.