1. Mix all marinade ingredients with sliced flank steak and marinate 2-3 hours or overnight.
2. In wok, heat oil until very hot, add beef mixture in small portions. Cook until done and remove from wok and put in strainer to let drain.
3. In wok, add more oil, add garlic, then approx. 1 cup of chicken broth.
4. Mix 3 tbsps cornstarch and 1/2 cup chicken broth. Add to mixture in wok to thicken.
5. Take 5 egg whites (beaten with chop sticks), add slowly to broth mixture (several tsp. at a time) and let egg whites cook in hot broth.
6. When egg whites are done, add scallions (chopped or sliced lengthwise).
7. When ready to serve, add cooked beef and heat through.
8. Serve immediately with rice or noodles.