Mongolian beef is thinly sliced beef marinaded for flavor then stir fried until crisped and served in a sweet and savory sauce with onions and peppers.
Cut the beef into thin, bite size pieces, against the grain.
Combine marinade ingredients in a dish and add beef. Let marinade for at least 30 minutes and up to 2 hours.
Mix sauce ingredients in a bowl and set aside.
Heat half the cooking oil over high heat until it just starts to smoke.
Drain any excess marinade from beef and lightly dust with cornstarch.
Cook the beef in two or more batches (to prevent lowering the heat of the wok pan) for about 1-2 minutes, or until juices run clear. Remove beef with a slotted spoon and set aside.
Repeat with second half of oil and second batch.
Add onions and stir fry until translucent, about 1 minute.
Add garlic and ginger and stir fry for about 30 seconds.
Add the green onions and beef (reserving some green onions for the garnish).
Add the sauce mixture and cook for about 2 minutes, or until sauce has thickened.
Garnish with green onions and serve over white rice or crispy noodles.
Notes
Place the beef in the freezer for about 15-30 minutes to make it easier to slice thinly.
Slice the beef against the grain to ensure it stays nice and tender.
Use a wok or a saucepan to fry the beef for the best crispy results.
Cook the beef in batches to ensure it gets crisp on the outside. If you put too much beef in the wok/pan at a time, you will steam it instead of fry it and the results won't be the same;
You can substitute flank steak or skirt steak for the flap meat.
Substitute sherry for the Shaoxing wine if desired.
6. Make it spicy by adding chili paste or sriracha.