Prep all ingredients by dicing onion, mincing garlic, chopping sun-dried tomatoes, and cutting chicken into bite-sized chunks.

Melt butter in a large pot over medium heat. Add onion and sauté until softened.

Stir in garlic, Italian seasoning, salt, pepper, and optional chili flakes. Cook for about 1 minute.

Add chicken broth and chicken pieces along with sun-dried tomatoes. Simmer for 12-15 minutes.

Cook pasta separately according to package instructions until al dente, then drain.

Whisk together half-and-half and cornstarch until smooth. Add to soup to thicken.

Shred cooked chicken in the pot, then add cooked pasta and spinach. Stir until spinach wilts.

Serve hot, topped with ricotta, parmesan, and mozzarella.