Mix ground meat, breadcrumbs, Parmesan, egg, salt, and pepper. Form into 1-inch meatballs.
Heat oil in pot, cook meatballs until browned (5-7 mins), then set aside.
In the same pot, add diced onion, carrots, and celery. Cook until vegetables are softened, about 5 minutes.
Pour in the chicken broth and bring the mixture to a simmer.
Add the small pasta to the pot and cook according to package instructions until al dente, usually about 8-10 minutes.
After pasta cooks, return meatballs, add spinach/kale. Simmer 2-3 mins till greens wilt, meatballs heat through.
Taste the soup and adjust seasoning with salt and pepper if needed.
Ladle the soup into bowls and garnish with additional grated Parmesan cheese if desired. Serve hot and enjoy!