In pot, heat 1 tbs oil over medium-high heat. Add onion, Italian seasoning, 1/2 tsp salt and 1/4 tsp pepper;cook, stirring, until onion is tender, 2-3 minutes. Add meatballs; cook, stirring occasionally, until browned, 3-4 minutes. Add broth and 2 cups of water;bring to a boil. Add pasta and cook until tender, 10 minutes.Stir in spinach and cook until heated through,1-2 minutes. If desired,serve topped with shredded parmesan cheese.