Mongolian Beef

1. Cut tops of green onions into 2" long pieces.
2. Combine sauce ingredients in small bowl & stir thoroughly.
3. Cut steak across the grain into thin slices, about 1/2" deep by 2" long.
4. In bowl big enough to hold meat, combine egg whites, salt & water chestnut flour.
5. Beat with chopstick until frothy.
6. Add steak, & use fingers to coat each slice.
7. Deep-frying: In wok, heat oil to moderately hot. When ready, piece of coated meat will rise to surface immediately.
8. Fryi meat in small batches; drop in 1 slice at a time to avoid sticking.
9. Cook until lightly brown, about 1 minute.
10. Drain on Chinese strainer or paper bag. Stir-frying: Remove all but 2 T of oil from wok. With wok at medium heat, quickly stir-fry green onions & ginger for about 20 seconds.
11. Add sauce; bring to boil on high heat while stirring.
12. Add beef all at once, & toss with sauce until beef is hot & coated.
13. Push beef out of sauce, dribble in cornstarch paste to lightly thicken.
14. Recombine.
15. Serve immediately.