In fact, it's not an English item as far as anyone knows -- in England, 'London broil' doesn't actually mean anything. It's not a dish or a cut of meat either, but rather a type of cooking method ...

When the term "London broil" first spread through America, it referred to a lean cut of beef, like flank steak or round, tenderized with a marinade before cooked under a broiler and sliced against ...

There's the London broil method, which involves marinating a lean cut of meat for a period of time before cooking it quickly (but never beyond medium, or it'll be too chewy). Some marinades ...