Heat oil in a large stockpot over medium-high heat. Add onion, carrots, celery, mushrooms, garlic, and Italian seasoning and sauté until softens, about 8-10 minutes.
Stir in cooked chicken, tomato sauce, chicken broth, corn, and green beans. Bring to a simmer and cook for 15-20 minutes.
Season with salt and pepper to your taste, then sprinkle with Parmesan cheese and fresh chopped parsley.
Enjoy while hot!
Notes
Chicken: Use any leftover chicken, rotisserie chicken, or cook your own chicken breast.Veggies: Use any veggies you have handy like green beans, peas, celery, and carrots. You may use fresh or frozen veggies.