Preheat oven to 400°.
To prepare meatballs, combine the first 10 ingredients in a bowl; shape mixture into 48 (1-inch) meatballs. Place meatballs on a jelly-roll pan coated with cooking spray. Bake at 400° for 20 minutes or until done.
To prepare soup, bring water and broth to a boil in a Dutch oven. Add celery, onions, and frozen vegetables; cook 10 minutes or until vegetables are tender. Add pasta; cook 8 minutes or until done. Add meatballs; cook 2 minutes or until thoroughly heated. Place 6 meatballs in each of 8 bowls; divide soup among bowls. Sprinkle evenly with parsley.