1. Heat the olive oil in a large pot or Dutch oven over medium heat. Add the diced onion and cook until softened.

2. Stir in the garlic and cook for about 30 seconds until fragrant.

3. Add the chicken, Italian seasoning, salt, black pepper, and red pepper flakes. Cook until the chicken is lightly golden and nearly cooked through.

4. Pour in the chicken broth and add the sun-dried tomatoes. Bring the soup to a gentle simmer.

5. Lower the heat and stir in the heavy cream and Parmesan cheese until the broth is smooth.

6. Add the cheese tortellini and cook until tender according to package timing, stirring occasionally.

7. Stir in the fresh spinach and cook just until wilted.

8. Taste and adjust seasoning if needed, then serve hot with extra Parmesan on top.