-warmed (5 oz) Drain pineapple; reserve juice. Combine juice with ketchup, vinegar, brown sugar, cornstarch and soy sauce; stir to blend. Heat oil in wok or large skillet. Add chicken; stir fry 3 minutes. Remove chicken. Add bell pepper and onion; stir fry 3 minutes. Add water chestnuts and juice mixture. Cook, stirring, until boils and thickens. Add chicken and pineapple; heat through. Serve over chow mein noodles.