Mongolian Beef

Slice thinly, against the grain:

Flank Steak

Slice lengthwise and slightly diagonally:

1 Leek

Marinade Flank Steak and 1/2 of Sliced Leek in:

Soy Sauce
Garlic (powder or chopped)
Peanut Butter
Ginger (powder or diced)
Hoisin Sauce
White Wine (or Sake)
Rice Vinegar
Sugar to taste

Optional: Slice as for Stir Fry

Carrot
Mushrooms
Cabbage
Broccoli
Onion
Etc.

Deep Fat Fry in Corn or Peanut Oil:

Mai Fun Noodles

Break out as much noodles as you want to prepare into small bundles prior to putting any in to fry. The oil should be around 400 F. To see if it's hot enough, drop a noodle in. If it poofs out, it's hot enough. If it just kind of sits there, it's not. If you can't tell, it's not hot enough. Have a plate with paper towel on it handy to put the noodles on after they are fried. The noodles fry instantaneously so be ready to take them out as soon as you put them in.

Velvet Marinaded Beef in Oil:

Basically dip the beef into the hot oil (doesn't need to be quite as hot any more), swirl it around and when it quits making quite so much noise pull it back out again. The whole routine takes a smidge under a minute. The meat should not be fully cooked.

Stir-Fry Beef in small amount of Oil, with Vegetables from Above (if used), Bean Sprouts (if desired) and other half of Leek. Use the rest of the marinade as sauce, and eke out with additional white wine or sake. The less liquid added, the more the sauce will cling to the beef. Serve over Mai Fun noodles with steamed rice.