1-1/2 lb. flank steak
1/4 cup water
2 tablespoons soy sauce
1 teaspoon vinegar
1 clove garlic, minced
1/2 teaspoon dry mustard
1 (8 ounce) can tomato sauce
1/2 cup water chestnuts
1 sliced green pepper
1/4 cup water
1/4 cup cooking oil
Thinly slice partially frozen steak diagonally across grain to 2 1/2-3 inch strips. Combine soy sauce, vinegar, garlic and mustard. Blend thoroughly, pour over steak. Marinate 1 hour. Combine tomato sauce, water chestnuts, water and green pepper; blend well. Add oil to pan/wok. Preheat at 325 degrees on wok. Stir fry meat until well done in middle. Add sauce mixture and bring to boil without stirring. Cook additional 1 minute. Serve over rice!