Core the apple with an apple cutter and cut into fine slices. Put the butter in a pan and fry the apple slices in it until golden brown. Cut the red onion and spring onions into fine rings. Mix the crème fraîche or crème légère with the jam and milk, season with salt.
Spread half of the still warm apple slices on the plates, place the matjes fillets on top and place the other slices on top. Now distribute the onion rings over the fillets and draw a ring with the cranberry cream around them.
Fried potatoes or a colorful salad taste best with it.