Preheat oven to 350°.
Meatballs first! Combine all the meatball ingredients in a big bowl. This is a good time to get your hands dirty and really make sure everything’s mixed well.
Roll into meatballs about the size of a nickel and place on a baking sheet. You want the final meatball to be bite-sized, but keep in mind they’ll shrink while baking.
Bake at 350° for around 20 minutes, until just barely cooked through.
While the meatballs are baking, get started on chopping the onions, carrots, celery, and garlic.
Sauté the vegetables in a big stockpot for five minutes or until the onions are just turning translucent.
Add the chicken broth and simmer for 10-15 minutes, until the carrots and celery are almost cooked through.
Stir in the acini de pepe followed by the spinach. Cook for 5-7 minutes, until the pasta is just barely al dente – it will continue to cook in the hot broth.
Ladle into bowls, add meatballs, and top with parmesan.