Preheat the oven to 350 degrees F.
For the meatballs:
Place the ground chicken, sausage, bread crumbs, garlic, parsley, Pecorino,
Parmesan, milk, egg, 1 teaspoon salt, and 1/2 teaspoon pepper in a bowl and
combine gently with a fork. With a teaspoon, drop 1 to 1 1/4-inch Meatballs onto
a sheet pan lined with parchment paper. (You should have about 40 meatballs.
Bake for 30 minutes, until cooked through and lightly browned. Set aside.
For the soup:
Heat the olive oil over medium-low heat in a large heavy-bottomed soup pot. Add
the onion, carrots, and celery and sauté until softened, 5 to 6 minutes,
stirring occasionally. Add the chicken stock and wine and bring to a boil. Add
the pasta to the simmering broth and cook for 6 to 8 minutes, until the pasta is
tender. Add the fresh dill and then the meatballs to the soup and simmer for 1
minute. Taste for salt and pepper. Stir in the fresh spinach and cook for 1
minute, until the spinach is just wilted.
Ladle into soup bowls and sprinkle each serving with extra grated Parmesan.