1.Cut the slice beef into 1/3-inch thick peices across the grain.
2.Marinade the beef with 1.5 Tbsps Chinese cooking wine, 1/4 tsp salt, 1/2 tbsp soy sauce, 2 Tbsps cornstarch, Mix until well combined.
3.Once done, let the coated chicken rest on a try for 20 minutes so the starch has enough time to bond together, and it will fall off less when deep frying.
5.While waiting, add 2.5 Tbsps soy sauce, 3.5 Tbsps brown sugar, 1 Tbsp oyster sauce, 2 tsps of dark soy sauce, 1/2 tsp of ground black pepper, 1 Tbsp cornstarch, and ½ cup water into a bowl and mix well.
6.Heat oil in frying pan. Fry the beef in 2 batches over medium heat, about 3 - 4 minutes for each batch. Use a sieve to eliminate the starch crumbs in between the frying.
7.Once the beef is done frying, remove from the oil and set it aside.
8.Pour most of the oil out, but leave 1.5 tsp in the pan. Add minced garlic, ginger, and a white part of the scallion. Stir over medium heat for 2-3 minutes or until the aromatics are slightly golden on the edge. Pour the sauce and keep mixing until the sauce thickens.
9.Introduce the beef back into the pan, along with the green part of the scallions. Toss everything until the beef is coated nicely. Serve with white rice (and egg roll.)