1Heat oven to 400ºF. Heat chicken, onions, celery, mixed vegetables and chicken broth to boiling in 5-quart Dutch oven. Stir cornstarch into cold water until dissolved; stir into chicken mixture. Heat to boiling, stirring constantly. Boil and stir 1 minute; remove from heat. Stir in parsley. Pour into ungreased rectangular pan, 13x9x2 inches.
2Stir Bisquick mix and milk until soft dough forms. Drop by 30 teaspoonfuls onto chicken mixture.
3Bake 25 to 30 minutes or until biscuits are golden brown.