1lbbeef flank, rump, or sirloin steak, cut against the grain
Black pepper sauce
Mix all of the sauce ingredients together, whisk thoroughly to incorporate the cornstarch in the cold liquids. If you don't have whole pepper corns, a little less of cracked pepper, do not use the ground up dusty powder.
Prep all of your ingredients, mince the garlic and ginger, cut the onion and bell peppers into short strips and thinly slice the beef against the grain. It helps if the beef is partially frozen to achieve very thin slices, sprinkle the beef with a little soy sauce to season it.
Heat a wok or large pan on high heat, add a bit of oil and cook the beef in batches. Remove from the pan before completely cooked, it's okay if there are still some uncooked spots, it'll finish cooking while it rests and again when you add it to the sauce later.
Add a little more oil to the empty wok and fry the garlic and ginger for 1 minute.
Add the onions and cook for 3 minutes stirring often to prevent scorching. Add the bell peppers and cook for an additional 3 minutes.
When the vegetables have a little color add the sauce and cook till thickened, now is the time to taste and adjust.
Add in the cooked beef and stir everything together, let sit off the heat for a moment to allow the beef to warm back up. Serve over rice.