While the chicken's cooking heat the sundried tomato oil in a large Dutch oven, or other heavy bottomed soup pot, set over medium heat.
2 1/2 tbsp sun dried tomato oil
Add the onions, season with salt, and saute until they're soft and translucent. Add the tomatoes and garlic and saute for 60 seconds.
1 large yellow onion, salt, 1 10 oz jar sun dried tomatoes in oil, 6 cloves garlic
Turn the heat up to medium high and add 1 cup of broth to the pot and simmer for 2 minutes. Stir with a sturdy wooden spoon to dislodge any browned bits stuck to the bottom of the pan.
6 cups chicken broth
Add the rest of the broth and the Italian seasoning to the pot, stirring to combine, and bring to a boil. Reduce the heat to medium low and simmer for 10 minutes.
1 tbsp Italian seasoning
Add the pasta, stirring in to evenly incorporate, and cook until al dente (about 15 minutes).
2 cups short pasta
Remove the pot from heat and add the chicken, cream, cheeses, and spinach. Stir gently to evenly combine and then let the soup rest just until the spinach has wilted.
1/2 - 1 cup heavy cream, 1/4 cup grated Parmesan cheese, 1/4 cup grated Pecorino Romano cheese, 2 cups fresh baby spinach leaves
Ladle into bowls and serve warm with crusty bread for dipping.