Place shredded chicken (or turkey) in a 9×13 baking dish.
Combine chicken stock, cream of chicken soup, and poultry seasoning in a medium bowl whisk until smooth, pour over chicken.
In the same bowl (no need to clean) add flour, baking powder, salt, pepper, buttermilk whisk until smooth and then slowly add in butter as you whisk until light and fluffy.
Pour batter over chicken, place in preheated oven and bake for 45 minutes or until bubbly and brown on top.
Notes
note: sometimes I will purchase a roaster chicken from the grocery store just for the purpose of making this dish. Otherwise I use left over bone in roasted chicken or turkey. Buttermilk: If you find you do not have buttermilk on hand, you can measure out 1 cup of whole milk or half and half, minus one tablespoon, and then add 1 tablespoon of white vinegar. Give a stir and allow to set for a few minutes. Voila it's as good as buttermilk!