Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the shredded chicken, cream of chicken soup, sour cream, chicken broth, and seasoning (garlic powder, onion powder, and black pepper). Mix well until combined.
Gently fold in the frozen mixed vegetables.
Add the stuffing mix to the chicken mixture and stir until everything is evenly distributed.
Grease the 9x13-inch baking dish with butter to prevent sticking.
Pour the chicken and stuffing mixture into the prepared baking dish, spreading it out evenly.
Cover the dish with aluminum foil and bake in the preheated oven for 30 minutes.
Remove the foil and bake for an additional 15 minutes, or until the top is golden brown and crispy.
Let it cool for a few minutes before serving.