Preheat oven to 425. Dip chicken in 1/2 cup buttermilk. Then roll chicken in mixture of flour, salt and pepper. Melt butter in a 9x13 pan. Place chicken in pan, breast side down. Bake 30 minutes uncovered. Turn chicken and bake 15 minutes. Turn chicken again and pour mixture of 1 cup buttermilk and mushroom soup over chicken. Bake 15 more minutes. Remove and serve with pan gravy over rice or noodles.