Peel and roughly grate the potatoes. Then squeeze out well and season with nutmeg, salt and pepper.
Let the oil (e.g. rapeseed or sunflower oil) get hot in a large pan, add the grated potatoes, press firmly and then fry on each side for 10 - 12 minutes over medium heat. (To turn, simply place a plate or pot lid on the hash brown and turn the pan.)
If you like, you can add a piece of butter to the pan at the end and fry the hash browns for 1 - 2 minutes on each side.
In the meantime, make a dip from the sour cream, quark, horseradish and dill. Squeeze half a lemon and season the dip with the juice, salt and pepper.
The finished rösti e.g., spread with the dip and top with salmon.