Bring homemade chicken broth to a simmer in a large pot.
In a large bowl mix together ground pork, ground beef, egg, pecorino romano cheese, parsley, garlic, salt and pepper.
Roll mixture into small meatballs, no larger than 1 inch.
Gently drop meatballs into broth and simmer until cooked through. They typically start to float in broth when they are done.
Add spinach and simmer for 2 minutes.
Serve immediately and garnish with pecorino romano cheese.