For meatballs: In a large bowl, combine the egg, milk, mustard, and salt. Stir in bread crumbs. Add ground meat and mix well. Shape into 48, 3/4-inch meatballs. Place in a shallow baking pan and bake in a 375 degree F oven for 15 minutes or until no longer pink. Drain well. If you like, transfer meatballs to a bowl. Cover and chill until serving time.

For soup toppers: Coarsely chop tomatoes. Heat bacon according to package directions and crumble. Place tomatoes, bacon, mushrooms, cheeses and croutons in individual bowls. Cover until serving time.

For soup, in a Dutch oven or pot, combine the water, tomato juice, and bouillon granules. Bring to boiling over medium-high heat. Add meatballs, pasta, and carrots. Cook, uncovered, for 10 minutes or until pasta is tender. Stir in green onions and bring to boiling. Stir in parsley.

To serve, ladle immediately into soup bowls. Let guests choose their own soup toppers. Makes 6 main-dish servings.