Peel the potatoes, wash and pat dry. Cut 1 / 2cm thin slices so that they are still connected at the bottom. It is helpful to place the potatoes on a tablespoon. Grease the shape. Place the potatoes close together with the incised side facing up, season with salt and cover with flakes of butter. Put the pan with the potatoes in a preheated oven (200 ° degrees) and cook for 50-60 minutes. About 10 minutes before the end of the baking time, brush again with the drained butter and sprinkle with Parmesan cheese.