Preheat the oven to 350°F (175°C).
In a large bowl, mix together the shredded turkey, cream of celery soup, chicken broth, garlic powder, onion powder, sage, oregano, salt, and pepper until well blended.
Fold in the cornbread stuffing mix and frozen vegetable medley, ensuring even distribution.
Transfer the mixture into a greased 9x13-inch baking dish, smoothing it out to create an even layer.
Top the casserole with grated mozzarella cheese.
Cover the dish with foil and bake for 25 minutes.
Remove the foil and continue baking for an additional 10-15 minutes, or until the cheese is melted and golden.
Allow the dish to rest for a few moments before serving.