Combine ground meat, bread crumbs, egg, parsley, minced garlic and salt and pepper in mixing bowl. Mix well with fork and form into tiny meat balls with your hands (traditional meatballs are about the diameter of a penny).
Place meatballs on greased baking sheet and bake about 25 minutes at 350°, until brown. (See variation below). About 10 minutes before serving, bring chicken broth to boil, add spinach and cook until tender. Add meatballs and return soup to a simmer. Stir in Pecorino cheese and serve. (When adding orzo, allow enough time for pasta to cook.)
Variation: saute meatballs in olive oil until brown and proceed with recipe above, or bring chicken stock to low boil, add uncooked meatballs, simmer about 25 minutes, add spinach, cook until tender, stir in cheese and serve.