For the meatballs: Combine ground beef, hot Italian sausage, parsley, 2 cloves minced garlic, egg, grated Parmigiana Reggiano, grated Pecorino Romano, panko breadcrumbs, Italian breadcrumbs, 2 tsp Italian seasoning, a pinch of salt, and red pepper flakes. Shape the mixture into 1-inch meatballs.
For the soup: Prep all soup ingredients. Roll the meatball mixture into 1-inch balls. Heat a large pot or Dutch oven on medium heat and add a bit of olive oil. Cook meatballs in batches until browned, then remove and set aside. Add the diced onion, 4 cloves minced garlic, sliced carrot, and sliced celery to the pot. Season with salt, pepper, and Italian seasoning. Cook until softened, about 7 minutes. Add the chicken broth, water, and dry white wine. Add the bundle of rosemary and thyme, Parmesan rind, and bay leaves. Bring the soup to a simmer. Skim any fat that rises to the top. Remove the herb bundle, bay leaves, and Parmesan rind from the soup. Add the acini di pepe (or pasta of choice) and cook according to package instructions. Return the meatballs to the pot to warm through, then add the spinach. Once the spinach is wilted, the soup is ready to serve. Top with Parmesan or Grana Padano and enjoy.
