Prepare meatballs: Place ground meats, bread crumbs, garlic, parsley, Parmesan, milk, egg, 1 teaspoons salt and 1/2 teaspoons pepper in a bowl and combine gently with a fork. With a teaspoon, drop 1-inch meatballs onto a sheet pan lined with parchment paper (you’ll make somewhere around 40 meatballs). Bake for 30 minutes, until cooked through and lightly browned. Set aside.
Prepare soup: Heat olive oil over medium-low heat in a large stock pot. Add onion, carrots, and celery and saute until softened, 5 to 6 minutes, stirring occasionally. Add the chicken broth and wine and bring to a boil. Add pasta to the simmering broth and cook an additional 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 spinach and cook for 1 minute, until spinach is just wilted. Ladle into soup bowls and sprinkle each serving with extra grated Parmesan cheese.