Prepare chicken chunks as directed on package. While chicken is baking, heat water to boiling in 3-quart saucepan. Add frozen vegetables; reduce heat to medium. Cover and cook 5 to 6 minutes or until hot; drain. Return vegetables to saucepan.
Stir chicken, pineapple and sweet-and-sour sauce into vegetables in saucepan. Cook over medium heat 3 to 4 minutes, stirring occasionally, until hot.