Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   1 1/2  pounds        beef round -- very thinly sliced
   3      tablespoons   soy sauce -- divided
   3      tablespoons   vegetable oil -- divided
   1      medium        onion -- cut in thin strips
   1                    green pepper -- cut in thin strips
   1      small   can   pineapple tidbits in light syrup -- drain reserve juice
     1/3  cup           vinegar
   2      tablespoons   cornstarch
     1/2  cup           brown sugar -- packed
     1/4  cup           walnuts -- large pieces
   6      servings      hot cooked rice

Preparation:

Place sliced beef in 2 tablespoons soy sauce to marinate. Heat 1 tablespoon oil in wok until hot. Add onions and green pepper and stir fry for 5 minutes. Remove from wok. Add 2 tablespoons oil to wok. Add beef and cook until brown, about 5 minutes. Remove from wok. Mix together brown sugar and cornstarch. Stir in vinegar, reserved pineapple juice and 1 tablespoon soy sauce until smooth. Pour into wok; cook over medium heat, stirring constantly, until mixture thickens and boils. Boil and stir 1 minute. Add meat, pineapple, green peppers and walnuts. Heat through. Serve over hot cooked rice.