Heat oil in large pot or dutch oven on medium heat.
Add diced onion and cook for 2-3 minutes.
Add Italian sausage, breaking up the meat with a wooden spoon, until browned.
Add dried herbs.
Add diced tomatoes, tomato sauce and chicken broth.
Bring to a boil.
Add spinach in batches, letting it wilt before adding more.
Once all the spinach is in the pot, pour in the tortellini and cook according to the package directions, usually about 7-8 minutes.
Add salt and pepper the soup to taste.
Ladle into bowls for serving, and enjoy!