In a small stock pot or dutch oven heat oil over medium heat. Add diced onion and cook until softened and translucent. Add minced garlic and cook for a minute more.
Add chicken broth, tomatoes, seasoning.Give it a stir. Bring to a boil over high or medium-high heat. Add tortellini. Cook for about 10 minutes. Stir in fresh spinach. Cook until spinach is wilted, about 2 minutes. Add salt and pepper to taste.