In a large pot, heat 2 tablespoons of oil over medium heat. Add 1.5 cups of diced onion and sauté for 3-4 minutes until the onions are softened and translucent.

Stir in 5 minced garlic cloves and cook for an additional 30 seconds.

Add 3 tablespoons of tomato paste and 0.5 cup of chopped sun-dried tomatoes, stir well. Cook for about 2 minutes.

Pour 8 cups of low-sodium chicken broth and bring to a boil. Reduce heat and stir in 1 cup of heavy cream, 1 tablespoon of basil, 2 teaspoons of salt, 2 teaspoons of Italian seasoning, and 0.25 teaspoon of red pepper flakes. Allow to simmer for 12 minutes.

Add 8 ounces of pasta to the pot and cook until al dente, about 10-12 minutes.

Lower the heat and gently add 3 cups of chopped spinach, 2 cups of cooked chicken, 8 ounces of cream cheese, and 2.5 ounces of Parmesan, stirring until cheese melts and spinach wilts, about 5 minutes.

Ladle soup into bowls and top with additional Parmesan and basil if desired.