- Slice beef into very thin strips.
- Mix cornstarch, broth, soy and sugar until smooth. Set aside.
- Heat 1 tablespoon oil in saucepot or wok over high heat. Add beef in 2 batches and stir-fry until browned. Set beef aside.
- Add 1 tablespoon oil. Add the mushrooms, cabbage, peppers, celery and green onions in 2 batches and stir-fry over medium heat until tender-crisp. Set vegetables aside.
- Stir cornstarch mixture and add. Cook until mixture boils and thickens, stirring constantly. Return beef and vegetables to saucepot and heat through. Serve over rice.