Pork ribs wash, dry. Salt, sprinkle with rosemary and marinate in the sour cream. Roll the ribs around and fasten with a wooden skewer, place in a baking dish. Potatoes clean, cut into large slices, mushrooms washed and add to the potatoes and season with salt and pour sour cream, mix well. Put the potatoes with mushrooms in the resulting edge of the circle. Close foil. Bake in the oven for 1.5 hours. BON APPETIT!!!