Mix soy sauce, water, ginger, sugar, salt, pepper, garlic powder, and onion powder to make the sauce.
Heat oil in a wok or large skillet over medium-high heat. Cook beef until browned, then add broccoli and red pepper, stir-frying until vegetables are tender.
Pour in the sauce and bring to a simmer. Mix cornstarch with a little water to make a slurry and add to thicken the sauce.
Serve hot over rice or noodles.
Notes
Use high-quality beef for best flavor and tender results.