* Preheat oven to 325 degrees. * Coat a 2 1/2-quart casserole with cooking spray. * In a medium bowl, combine milk and oil. Gradually stir in flour, baking powder, and salt. Mix well into a dough consistency and set aside. * Place chicken breasts in bottom of casserole. Cover chicken with onion, celery, and carrots. Evenly sprinkle sage and pepper over vegetables; pour broth over dish. * Using the dough mixture, form 2-inch balls and drop into casserole. * Cover tightly and bake for 1 1/2 hours.