There are many recipes for London broil, but they typically involve marinating a flank steak in a mixture of vinegar, oil, garlic, and herbs, then grilling or broiling it until it is browned and slightly charred.
Remove excess fat from steak then score on both sides.
Place all theingredients in a shallow pan.
Place steak in pan, then turn over.
Marinate at least 3 hours or over-night, turning several times.
Place steak in broiler 3 inches from heat.
Broil each side 4 minutes.
Slice thin across grain diagonally.