Brown chicken. Add green peppers, onions, tomatoes & celery. Simmer covered for 15 minutes.
Combine remaining ingredients except cornstarch and water in a small saucepan. Heat just to boiling point, stirring constantly.
Pour sauce over chicken and vegetables. Cover and cook over low heat for about an hour or until chicken is fork-tender.
If sauce is thin, thicken with corn starch dissolved in cold water