Slice beef thinly across the grain. Add 1 tablespoon soy sauce and set aside to marinate while you get everything else ready.
Mix together the broth, soy sauce, cornstarch and ginger and set aside. Spray a cold frying pan or wok with non-stick spray and heat to mid high heat.
Add broccoli, mushrooms, red pepper and green onions. Cook, stirring at all times, for 3 or 4 minutes. Vegetables will be tender but still crisp. Remove vegetables from wok.
Add the oil to the wok, being careful as the pan is quite hot. Add beef slices and stir fry for 2 or 3 minutes until beef is just slightly pink in the center. Push the beef away from the center of the pan.
Stir the sauce mixture again then add to the center of the pan. Cook the sauce with the beef, stirring at all times, until the sauce thickens and bubbles.
Return the vegetables to the wok or pan. Stir all together until everything is well coated and heated through.
Serve over hot cooked rice, or alone if you want a meal lower in carbohydrates.