Heat the Olive Oil: In a large soup pot or Dutch oven, warm 2 tablespoons of olive oil over medium-high heat.
Cook the Chicken: Add 1-1½ pounds of diced boneless, skinless chicken breasts or thighs, along with 1 teaspoon of Italian seasoning, salt, and pepper.
Sauté the Vegetables: Toss in ½ cup of diced onions, ½ cup of diced carrots, ½ cup of diced celery, ¼ cup of sundried tomatoes, and 3 minced garlic cloves.
Thicken the Soup: Sprinkle ¼ cup of flour into the pot and stir well to combine, followed by 2 tablespoons of tomato paste if desired.
Add the Broth: Gradually whisk in 6-8 cups of chicken broth, starting with 6 cups.
Incorporate the Pasta: Stir in 6 ounces of pasta along with the remaining 1 teaspoon of Italian seasoning, additional salt, and pepper to taste.
Add Cream and Spinach: Stir in 1 cup of heavy whipping cream, 2½-3 cups of fresh spinach, and ½ to 1 cup of grated Parmesan cheese.
Finish with Optional Ingredients: If desired, mix in cooked bacon, Cajun seasoning, or a splash of dry white wine.