Sweet and Sour Chicken (or pork)

Marinate chicken in:
2 tbsp pineapple juice
2 tbsp soy sauce
2 tbsp cornstarch
mix until smooth and coat meat well. chill 20 minutes

Stir fry chicken in oil , drain meat and set aside. Stir-fry veggies like onions, peppers, baby corn, etc. until tender, add chicken in pan. Add sauce bring to a boil, add 15 oz drained pineapple chunks, boil 1 minute. Serve over rice.

Sauce:
3 tbsp pineapple juice
2 tbsp soy sauce
3 tbsp cornstarch
2/3 cup sugar
1/2 cup ketchup
1/4 cup white vinegar
2/3 cup water
Mix until smooth, if made ahead stir before adding to pan.