In a bowl, mix together soy sauce, rice wine vinegar, sugar, cornstarch, and ginger. Add sliced meat to bowl and toss with hands. Set aside.
Heat oil in a heavy skillet (iron is best) or wok over high heat. Add snow peas and stir for 45 seconds. Remove to a separate plate. Set aside.
Allow pan to get very hot again. With tongs, add half the meat mixture, leaving most of the marinade still in the bowl. Add half the onions. Spread out meat as you add it to pan, but do not stir for a good minute. (You want the meat to get as brown as possible in as short amount a time as possible.) Turn meat to the other side and cook for another 30 seconds. Remove to a clean plate.
Repeat with other half of meat and onions, allowing pan to get very hot again first. After turning it, add the first plateful of meat, the rest of the marinade, and the snow peas. Stir over high heat for 30 seconds, then turn off heat. Check seasonings and add salt only if it needs it. Mixture will thicken as it sits.
Serve immediately over rice. If desired, sprinkle crushed red pepper over the top to give it some spice.
by The Savvy Kitchen