If desired, partially freeze beef for easier slicing. Trim fat from beef. Thinly slice beef across the grain into bite-size strips. Set aside. For sauce: In a small bowl, stir together beef broth, soy sauce, cornstarch, and ginger; set aside.
Lightly coat an unheated wok or large nonstick skillet with nonstick cooking spray. Preheat over medium-high heat. Add mushrooms and carrot; stir-fry for 2 minutes. Add broccoli and sweet pepper; stir-fry about 2 minutes more or until vegetables are crisp-tender. Remove vegetables from wok.
Carefully add oil to wok. Add beef; stir-fry for 2 to 3 minutes or until desired doneness. Push beef from center of wok. Stir sauce. Add sauce to center of wok. Cook and stir until thickened and bubbly.
Return vegetables to wok. Add green onions. Stir all ingredients together to coat with sauce; heat through. Serve immediately over hot cooked rice. Makes 4 servings (1 cup beef mixture with 1/2 cup rice per serving).