For the meatballs

1. Soak bread. In a large bowl, combine the bread, milk, egg, and salt. Stir until everything is well moistened. Allow to sit for about 10 minutes to soften.
2. Add meat and spices. Add the ground turkey, onion, cheese, garlic powder and dried parsley. Mix gently until thoroughly combined.
3. Make meatballs. Shape small meatballs (about 1 inch in diameter or less), using a teaspoon measuring spoon to make the meatballs. I use a small measuring scoop to get even sized meatballs. If the meat mixture sticks to your hands too much, moisten hands slightly with water.
4. Chill. Place the meatballs on a parchment-lined or lightly greased cookie sheet, and refrigerate them while you prepare the soup.

For the soup

1. Cook aromatics. Heat the olive oil in a very large (at least 6-quart) pot over medium heat. Add the onions and carrots. Sauté, stirring frequently, until the onions are translucent and beginning to brown, about 10 minutes. Add the garlic and cook until fragrant, about 1-2 minutes.
2. Simmer. Add the broth, oregano, and basil. Bring to a simmer, and cook gently for 10 minutes.
3. Add spinach. Add the partially thawed chopped spinach, and bring the soup back to a simmer, breaking up any clumps of frozen spinach.
4. Add meatballs. Gently drop the meatballs into the soup. Simmer the soup for 30 minutes or so, then stir in the orzo pasta. Continue to simmer until pasta is al dente, about 8 minutes.
5. Season. Season the soup with salt and pepper to taste.
6. Serve. Serve the soup garnished with freshly grated Parmesan or Asiago cheese, if desired.