Peel and wash the potatoes and grate them roughly in a bowl. Season with salt and set aside briefly. Roast sunflower seeds in a pan without fat at medium heat until light brown, let cool down.
Squeeze the potatoes well over a sieve and place them in a bowl. Fold in sunflower seeds. Stir egg yolks into the potatoes and season with salt and nutmeg. Wash and quarter the apple and remove the core.
Cut the apple quarters into fine cubes and mix with the apple-horseradish and season with salt and pepper. Wash the dill, shake dry and pluck the pennants. Heat oil in a pan and fry about 12 Rösti at medium heat until golden brown.
Drain the Rösti on kitchen paper and arrange 3 on each plate. Halve the salmon slices and spread on the Rösti. Sprinkle dill flags on top. Add the remaining dip.