In a small bowl, blend all sauce ingredients. Set aside.
Add 2 tablespoons oil to heated wok and stir fry beef till it loses its pink color. Remove to serving bowl.
Add 2 more tablespoons oil to same wok. Toss peanuts and chili peppers in the wok and stir fry until peppers turn dark red. Remove from wok and add to beef.
Lower heat. If necessary, add more oil. Stir fry green onions and garlic for several seconds. (Do not let garlic burn.)
Return beef, peanuts and peppers to wok and stir fry a few seconds to combine. Add water chestnuts and combined sauce ingredients and stir fry till heated through and thickened.
Makes 4 to 6 servings.