One of my family's favorite Asian dishes For easy meat slicing, prefreeze the beef, until almost frozen, this makes for easier slicing. For more heat increase the chili flakes.This is great served over rice.
Heat 1 tablespoon of oil in wok over high heat; add in onion and stir-fry for 2 minutes or until browned; remove onion to a bowl.
For the sauce; in a saucepan over medium-low heat; add in ginger, garlic red pepper flakes and soy sauce, water and black pepper.
Add in the brown sugar to the saucepan then increase the heat to medium and boil 2-3 minutes or until thickened; remove from heat.
Toss the beef strips with the cornstarch to coat; let sit for about 8-10 minutes.
Meanwhile heat 1 cup oil in the wok until hot but not smoking; add in the beef and saute for about 2 minutes or until the beef is just cooked through (you do not have to cook the beef completely as it will cook more after) remove with a slotted spoon to a paper towel remove the oil from the wok.
Return the wok back to the heat and put the meat back in the wok along with the onions; then add in the sauce and cook for 1 minute stirring.
Cook for about 1 minute more.
serve on rice and sprinkle a small amount of chopped onions over the top.