Heat the olive oil in a large soup pot or Dutch oven over medium-high heat. Add the chicken and 1 teaspoon of Italian Seasoning, salt and pepper to taste, and cook until browned on all sides, about 4-5 minutes.

In the same pot, add the onions, carrots, celery, sundried tomatoes, and garlic and cook until translucent, about 3-4 minutes.
 Sprinkle the flour throughout and stir well to combine.

Add the flour in stages to avoid excess drying. If you plan to add tomato paste, add it here and stir.
Gradually whisk in the chicken broth and stir repeatedly, ensuring there are no lumps. Deglaze the bottom of the pan using your spoon.

Bring the mixture to a rolling boil and add in the pasta and 1 teaspoon of Italian seasoning, salt, and pepper to taste. Add in the tortellini and cover the pot with the lid and lower the heat to low to let the soup simmer for about 10-15 minutes or until the pasta is al dente. Alternatively, you can boil the pasta separately and add it at the end.

Stir in the heavy cream, spinach, and grated Parmesan cheese, and let the soup simmer for an additional 5 minutes. Taste and adjust the seasoning with salt and spices if needed.