Creating Italian Meatball Soup is simple when you follow these steps:

1. Make the Meatballs: In a large bowl, combine ground beef, breadcrumbs, Parmesan cheese, parsley, egg, minced garlic, salt, and pepper. Mix until just combined. Form the mixture into small meatballs (about 1 inch in diameter).
2. Brown the Meatballs: In a large pot or Dutch oven, heat a little olive oil over medium heat. Add the meatballs, cooking until browned on all sides, about 5-7 minutes. Remove and set aside.
3. Sauté the Vegetables: In the same pot, add a bit more olive oil if necessary. Add chopped onions, carrots, and celery. Sauté until softened, about 5 minutes.
4. Add Broth and Tomatoes: Pour in the beef broth and diced tomatoes. Stir to combine.
5. Season the Soup: Add dried oregano, dried basil, and bay leaf to the pot. Bring the mixture to a simmer.
6. Return Meatballs: Gently place the browned meatballs back into the pot. Let everything simmer together for 20-25 minutes until the meatballs are cooked through and the flavors meld.
7. Adjust Seasoning: Taste and adjust seasoning with more salt or pepper, if necessary.
8. Serve Hot: Remove the bay leaf before serving. Ladle the soup into bowls and garnish with fresh basil leaves if desired.

These instructions will guide you in crafting a bowl of Italian Meatball Soup that is sure to impress.