Cut the pork into slides. Whip heavy cream with pinch of salt and add horseradish. Spread a pork slide with horseradish cream and put another pork slide on it, making a sandwich. Strain plums from vinegar and cut into big cubs. Fry walnuts on the dry pan and cut into pieces, add plums, gingerbread spice and a small amount of vinegar. Arrange pork sandwiches on the plate and serve with plums and walnuts.