Preheat the oven to 425 degrees F.
Put the chicken in a 2-quart casserole dish. Combine the broth and soup in a medium saucepan and bring the mixture to a boil. Pour the broth mixture over the chicken.
In a separate medium bowl, mix the flour with the pepper. Stir in the melted butter and the buttermilk. Pour this mixture over the casserole and smooth the top; do not stir. Bake the casserole until the crust is brown and the filling beneath is hot and bubbly, 45 minutes.
Recipe adapted from Georgia Cooking in an Oklahoma Kitchen by Trisha Yearwood (c) Clarkson Potter 2008