Mongolian Beef (PF Chang/PeiWei copycat)

Mongolian Beef
4 teaspoons vegetable oil, divided
1 1/2 cups cremini mushrooms, quartered
1 tsp. ginger, minced
2 Tbsp. garlic, chopped
1/2 cup soy sauce
1/2 cup water
1/2 cup brown sugar
Vegetable oil, for frying
1-1/2 lb flank steak
1/4 cup cornstarch
2 cups of two-inch lengths green onions
3 cups cooked rice or rice noodles

   Slice the beef, across the grain and at a 45 degree angle to get the thinnest slices possible.  I put my flank steak in the freezer for 1-2 hours so that it is almost, but not quite, frozen and easier to slice cleanly.

  Put the beef in a bowl or pan and add the cornstarch, tossing to coat each piece.  Let the beef sit for 10 minutes to allow the cornstarch to stick.  I kept the pieces big for this step and cut them into 2 inch bite sized pieces before frying.

  In a wok on medium-high heat add 2 tsp. of oil and the mushrooms. Quickly brown the outside of the mushrooms and then remove them from the wok and set aside.  Add the other 2 tsp. of oil and the garlic and ginger.  Stir and heat for 1 minute then add the soy sauce, water, and brown sugar.  Stir until the brown sugar is dissolved and the sauce thickens slightly, about 3 minutes.  Remove the sauce from the wok and set it aside. 

 With a paper towel wipe out the wok.  Return it to the heat and add 1 cup of oil for frying the beef.
Quickly fry the beef in small batches and remove to a plate lined with paper towels to absorb the extra oil.  The meat doesn't have to completely cook, you just want to brown and crisp it up around the edges.

  Pour out the excess oil and wipe out the wok.  Return it to the heat and add the meat and the sauce.  Stir to coat and then add the mushrooms and the green onions.  Cook for just under a minute.  Serve over rice or noodles.