Peel and wash the potatoes and grate them coarsely on a kitchen grater. Season with salt, pepper and nutmeg. Heat 1 tablespoon of oil in two pans and put 3 potato wedges next to each other in each pan.
Form into evenly round Rösti with a spatula. Fry on each side over medium heat for approx. 4 minutes. Keep the finished Rösti warm. Repeat the process 1 time. Whip the cream until stiff with the whisks of the hand mixer.
Add horseradish and season with salt, pepper and lemon juice. Pour into a disposable piping bag with star-shaped spout. Arrange the hash browns and salmon on plates. Garnish with creamed horseradish, cress and lemon.