To make this soup, start by preparing the mini meatballs. Add the ground beef, Italian sausage, panko, eggs, Parmigiano Reggiano, parsley, garlic powder, salt, and pepper to a large bowl.
Use clean hands to mix everything together until well combined. Roll the mixture into tiny meatballs, about 1 teaspoon each, and set them aside on a plate—you should get 40–50.
Next, heat a large non-stick skillet over medium heat. Add the meatballs and brown them on all sides, turning as needed. They don’t need to be fully cooked through at this stage, because they’ll finish cooking in the soup. Once browned, remove them from the skillet and set aside.
Then, in a large soup pot, heat the olive oil over medium heat. Dice the onion, celery, and carrots, mash the garlic, and add everything to the pot.
Sauté for 6–7 minutes, stirring occasionally, until the veggies have softened.
Add the dry pasta to the pot and stir for 1–2 minutes to lightly toast it.
Pour in the white wine to deglaze the pot, scraping up the browned bits from the bottom.
Add the chicken broth, lemon juice, bay leaves, and the browned meatballs. Stir everything together and bring the soup to a gentle boil.
Once it starts to bubble, reduce the heat to low, add the spinach, and let the soup simmer for 15 minutes so the flavors meld and the spinach wilts.
Remove the bay leaves, ladle into bowls, and finish with plenty of grated Parmigiano Reggiano and extra lemon juice if you’d like. Enjoy!