Combine sauce ingredients in a small bowl and set aside.
Heat 1 tablespoon of oil in wok over high heat. Add beef and stir fry, leaving it a little pink. Remove and place in bowl. Add more oil to wok and add broccoli, stir fry for about 2-3 minutes or until starting to brown in places. Add onions, garlic, and red bell pepper. Stir fry for about 2 more minutes or until onions are tender.
Add beef back to wok. If wok is smoking, you might need to turn heat down to medium high. Add sauce ingredients and stir until everything is coated.