Preheat oven to 425 degrees. With 3 tablespoons butter, grease 8 inch skillet with heat-resistant handle and tight-fitting cover. Gently toss potatoes with salt and pepper. Layer a third of potato slices, circular fashion, around bottom and sides of skillet. Dot with butter. Repeat twice. Over high heat, cook potatoes 55 minutes, let cook 3-5 minutes before serving.