Sauce

1. Heat 2 tsp. of vegetable oil in a medium saucepan over medium/low heat, without letting it get too hot.
2. Add ginger, garlic, soy sauce and water to the pan, being careful not to scorch the garlic.
3. Dissolve the brown sugar in the sauce, then increase the heat to medium and boil the sauce for 2-3 minutes or until the sauce thickens. Remove it from the heat and set aside.

Beef

1. Slice the flank steak against the grain at a 45 degree angle into 1/4″ thick bite-size slices.
2. Dip each piece into cornstarch and then let sit for 10 minutes.
3. As the beef sits, heat up one cup of oil in a wok over medium heat. You want it hot enough, but not smoking.
4. Add the beef to the oil and sauté until brown, cooking evenly on all sides.
5. After a couple of minutes, remove the cooked meat and place on paper towels.
6. Dab excess oil off meat and add to medium saucepan with the sauce in it. Put the pan back over medium/low heat.
7. Add chopped green onions and let sauce simmer until warm. Serve over rice.