Combine all meatball ingredients in a large bowl, mixing well. Roll the mixture into small balls, about 1/2 to 3/4 inch in size. Place them on a greased baking sheet and broil until golden brown.
In a large pot, heat olive oil over medium heat. Add onions, carrots, and celery, cooking until tender. This forms the flavorful base of your soup.
Add crushed tomatoes, tomato sauce, beef broth, Italian seasoning, salt, and pepper. Stir to combine and bring to a gentle simmer.
Carefully add the baked meatballs and pasta to the soup. Cook until the pasta is tender. Finish with fresh parsley and optional Parmesan before serving.