Tear bread into small pieces and place in a food processor or blender. Process until the bread is in fine crumbs.

In a large bowl, combine bread crumbs, beef, pork, cheese, egg, Italian seasoning, salt, pepper — don’t overmix. Let sit for 10-20 minutes.

Shape into 1″ balls (I get about 30-35) and place on a plate.

Heat 2 tablespoons of oil in a large soup pot or large Dutch oven over medium-high heat. Brown meatballs on both sides, about 2 minutes per side. They do not have to be cooked through. Remove from the pot and set aside. (*OPTIONAL: you can also bake the meatballs if you do not want the juices in the soup — see instructions below)

Add the carrots, celery, and onion (no need to clean out the pot!) and cook in the leftover fat from the meatballs for about 5 minutes or until crisp-tender.

Add tomato paste, garlic, Italian seasoning, salt, red pepper flakes, and bay leaf. Cook for 1 minute.

Stir in chicken broth, diced tomatoes, and Parmesan rind and use a wooden spoon to scrape the bottom of the pot to remove any browned bits. Bring to a simmer over medium-high heat.

Cook for 5 minutes, until the vegetables are almost tender.

Stir in the uncooked pasta and meatballs. Cover and reduce the heat to medium, then cook for 10 minutes or until pasta is al dente.

Stir in spinach and marinara sauce. Taste and adjust seasonings as desired. Serve.