Sweet and Sour Chicken

This recipe is one of my Grandma Carlson's recipes.  She was one of the best cooks ever!

1/2 to 1 cup water
5 Tbsp cornstarch
3/4 cup brown sugar, firmly packed
1 tsp salt
1 (20 oz) can pineapple chunks, drained (keep juice)
2 cups chicken (cooked, bite sized pieces)
2 Tbsp GF soy sauce
1/4 cup white vinegar
1/2 cup sliced or diced onions
1 green pepper, chopped
2 tomatoes, chopped

Drain pineapple, reserving the juice in a separate bowl.  In a saucepan combine water, cornstarch, brown sugar and salt. Stir until mixture is smooth.  Add the pineapple juice to the saucepan.  Cook over medium heat about 5 to 7 minutes, until mixture starts to thicken.  Add chicken, soy sauce, and vinegar.  Cover and simmer 15 minutes, stirring occasionally.  Add pineapple chunks, onions, and green peppers to chicken mixture.  Cook until vegetables are slightly tender.  Just before serving, stir in chopped tomato.  Serve over hot cooked rice.

Notes:
•  I like 1 cup water.  It makes the sauce not quite so strong.
•  I like to cut up the pineapple chunks.  You can also use tidbits.