Preheat your oven to 350°F (175°C).

In a skillet, sauté diced onion and celery until soft.

In a large mixing bowl, combine shredded turkey, sautéed onions and celery, cream of chicken soup, chicken broth, and milk.

Add the stuffing mix along with the garlic powder and poultry seasoning to the mixture.

Season with salt and pepper, adjusting to your taste.

Transfer the mixture into a greased 9x13-inch baking dish.

Cover the dish with aluminum foil and bake for 25 minutes.

Remove the foil and bake for an additional 10-15 minutes or until golden brown on top.

Allow the casserole to cool slightly before serving.