Steak a la Mongo

1 lg  Steak (cut of your choice)
1/2 C  Worcestershiresauce
1/2 C  Soy Sauce
2 tbs  Chinese Vinegar (dark vinegar)
2 tsp  Garlic powder
1 med  Vidalia Onion
1 C  Mushrooms, chopped

Marinate the steak for between 2-4 hrs.
Pierce it on both sides to allow the marinade to penetrate well if you use a thick cut.
Grill over an open flame. For best results, sear the heck out of it then cook slower until done.
For an awesome gravy, use a little bit of the marinade (made fresh) and mix with sauteed onions and mushrooms. 1