London Boil is our favorite way to eat steak! Most of us think London Broil is a cut of meat. Many grocery store meat departments and butcher shops sell a cut of beef labeled London Broil. Let's get it straight, London Broil is a cooking method usually using the Top Round Roast. Chef John gives step-by-step directions on how to defrost, cut, marinate and cook the top round roast “London Broil” method.