01 -
Tear bread into small pieces and place in a food processor or blender. Process until the bread is in fine crumbs.
02 -
In a large bowl, combine bread crumbs, beef, parmesan cheese, egg, Italian seasoning, salt, and pepper. Do not overmix. Let sit for 10-20 minutes.
03 -
Shape the mixture into 1-inch balls (approximately 30-35 meatballs) and place them on a plate.
04 -
Heat 2 tablespoons of oil in a large soup pot or Dutch oven over medium-high heat. Brown meatballs on both sides, about 2 minutes per side. Remove from the pot and set aside.
05 -
Add carrots, celery, and onion to the same pot and cook in the leftover fat for about 5 minutes or until crisp-tender.
06 -
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, scraping the bottom of the pot to remove any browned bits. Bring to a simmer over medium-high heat.
07 -
Cook for 5 minutes until the vegetables are almost tender. Stir in uncooked pasta and browned meatballs. Cover and reduce the heat to medium, then cook for 10 minutes or until pasta is al dente.
08 -
Stir in spinach and marinara sauce. Taste and adjust seasoning as desired. Serve warm.