For the rösti, boil the potatoes in well-salted water, drain, rinse and peel.
Leave in a baking dish with the lid closed for at least one night, better still 2 to 3 days.
Grate into long strips with a perforated grater. Heat the butter in a heavy frying pan.
Add the potatoes, salt and mix with the fat, then press together with a spatula to form a firm cake.
Roast until the bottom side is brown and crisp. Turn and toast the second side until golden brown as well.
Drain the rösti on paper towels, arrange and serve.
The Rösti is best served with shredded veal, veal stew, roasted chicken breasts, lamb chops or even fillet of beef.