Because it's just that good...
Marinade (I am a big fan of the dump & pour method- use your own amounts):
red wine vinegar
spicy brown mustard
fresh ground pepper
Place all ingredients in whatever container you plan to marinate your meat in (I use a zip-loc bag) Add meat:
3 lbs London Broil (beef)
Allow meat to marinate as long as you can, two days is best, but if your in a hurry 20 minutes is OK too. Grill meat (preferably on a charcoal grill) to done-ness desired (I like medium rare- just warm of mooing). Slice and enjoy.