Spinach Artichoke Tortellini Soup

Heat oil in a large pot over medium heat. Add onions and saute until softened, about 5 minutes. Add broth and artichoke hearts and bring to a boil. Drop in the tortellini and continue to boil for 3 minutes. Fold in the spinach and lemon zest and cook for another minute or two, until greens have wilted but are still bright green. Remove from heat and season with salt and pepper. Ladle into bowls and top with Parmesan cheese, if desired. Enjoy!