Sweet & Sour Chicken

1 cup pineapple
1 cup chopped onion
2 tbsp oil
1 1/4 cup water
2 cups carrot sticks
3 OXO cubes
1/4 cup brown sugar
2 tbsp cornstarch
1/4 tsp ginger
1/4 cup ketchup
2 tbsp vinegar
1 tbsp soya sauce
2 cups diced cooked chicken
1 green pepper