Cut chicken in 1" pieces and toss with a mixture of flour,salt and pepper. Drain pineapple reserving 2 cups of juice.
Heat oil in skillet. Saute chicken 5 minutes until brown. Add drained pineapple cover and cook over a low heat 55 minutes.
Mix soy sauce, cornstarch,vinegar and reserved pineapple juice. Stir in pan until thickened. Serve on hot rice or chinese noodles.