Set a large pot or Dutch oven over medium heat and add a splash of olive oil and half the butter.
Sauté the sliced mushrooms until golden brown and then set aside.
Add the rest of the butter and then sauté the onion, carrots, celery, and garlic until softened.
Sprinkle in the flour and stir for about a minute, letting it coat the vegetables and cook off the raw taste.
Slowly whisk in the turkey broth or chicken broth, scraping the bottom of the pot so no flavor is left behind.
Add the Italian seasoning, poultry seasoning (if using), bay leaf, mushrooms, salt, pepper, garlic salt, worcestershire, and chili oil.
Stir in the cooked chopped turkey and let everything simmer on medium-low heat for about 20–25 minutes until the veggies are tender and the soup is thickened slightly.
Taste and adjust seasonings, then stir in fresh parsley.
If you’re adding egg noodles, white rice, or wild rice blend, do that at the end and simmer just until tender.
Remove the bay leaf and serve hot with crusty bread.