Sweet & Sour Pineapple Chicken

2 cups green pepper
2 cups celery, sliced diagonally
2 tablespoons oil
1 tin (14 ounces) unsweetened pineapple tidbits (drained)
2 cups drained pineapple juice with water added to make up
5 tablespoons cornstarch
2/3 cup brown sugar
1/3 cup vinegar
1/4 cup soy sauce
4 cups left over chicken, cut in cubes
Hot cooked rice

Saute vegetables in oil until tender crisp. Remove from pan. Combine pineapple juice with water, cornstarch, brown sugar, vinegar and soy sauce in saucepan. Cook, stirring constantly until sauce thickens. Add drained pineapple, vegetables and chicken. Heat and serve with rice.