Broil the steak for 8 to 12 minutes, turning once. Put the broiler pan on the top rack of the oven and cook the steak four to six minutes on each side. A London broil that goes for 8 minutes will cook to rare, while a steak that cooks for 10 minutes will cook to medium-rare to rare. For a medium-well steak, a full 12 minutes may be necessary. Broiling the steak for too much longer will likely dry it out, however.