In a mixing bowl, combine the ground pork, ground beef, egg, breadcrumbs, Italian seasoning, grated Parmesan cheese, minced garlic, dried parsley, salt, and black pepper. Mix until well combined.

Shape the mixture into small 3/4 inch meatballs.

Heat olive oil in a non-stick pan over medium-high heat. Add the meatballs to the pan and sear them until they are browned on all sides. The meatballs do not need to be fully cooked at this stage.

Transfer the seared meatballs to a slow cooker.

To the slow cooker, add the diced celery, diced carrots, diced onion, minced garlic, chicken broth, Italian seasoning, salt, and pepper. Stir to combine.

Cook the soup on high for 4 hours or on low for 6-8 hours, until the flavors meld together and the vegetables are tender.

About 30 minutes before the soup is done, add the Acini de pepe pasta to the slow cooker. Stir to ensure the pasta is evenly distributed in the soup. Continue cooking for the remaining 30 minutes or until the pasta is cooked al dente.

When the soup is done, stir in the fresh spinach and allow it to wilt in the hot soup for about 5 minutes. Stir again to incorporate the spinach.

Serve the Italian wedding soup hot, garnished with grated Parmesan cheese and fresh parsley.