Preheat your oven to 350ºF.
Lightly spray a 9×13-inch pan with cooking spray.
Spread your chopped cooked chicken in the bottom of the dish.
In a separate bowl, mix together the can of cream of chicken soup, cream of celery soup, and sour cream. Stir until well combined.
Spread the creamy mixture evenly over the layer of chicken.
Next, sprinkle the uncooked stuffing over the soup mixture.
If your herb packet isn't mixed with the stuffing, top the stuffing with it now.
In a small bowl, mix together the chicken broth and melted butter. Pour this mixture evenly over everything in the dish.
Finally, bake uncovered for about 30 minutes.
Once baked, remove from the oven and let it cool for a few minutes.