Chicken with stems

7 cups chicken stock (preferably homemade) 2 medium carrots , cut into 1/4 inch dice 2 celery ribs , cut into 1/4 inch dice 1 onion , cut into 1/4 inch dice 4[...]

4 boneless chicken breasts (about 4 oz. each) salt and black pepper 8 slices prosciutto (thin slices) 2 ounces mozzarella cheese , cut into 1/2 oz. slices 1[...]