Slice the beef into thin strips that are 2-inch long and 1/4 inch thick (It’s best to cut against the grain). You can freeze the steak for about 30-45 minutes so that it’s much easier to cut into thin slices.
In a medium bowl, mix together soy sauce and cornstarch.
Add the beef and let marinate for 30 minutes or up to 4 hours. (If the marinating time is longer than 1 hour, cover with plastic wrap and store in the refrigerator.)
Place a wok or skillet on high heat, add 1 tablespoon oil.
When the oil is hot, add minced ginger and garlic.
Once fragrant, stir in marinated beef together with all the sauce. Don't overcrowd the pan, and cook in small batches if needed.
Cook for about 2-3 minutes. Then add brown sugar, beef broth (or water) and green onions and stir-fry for 1-2 minutes. Remove beef to a plate.
In the same wok, add another tablespoon oil, stir-fry the vegetables of your choice for 3-4 minutes or until cooked through.
Add back cooked beef and mix with the vegetables. (You can also add cooked noodles)
Remove from heat, sprinkle with green onions, serve and enjoy!