Despite indications to the contrary on Loyd Grossman’s Sunday Morster-Bate, rösti is a potato dish... period... and the secret of this delicious but calorific Swiss treatment for potatoes is lots of clarified butter, that is butter which has been heated to extract the residual milk solids.
Preheat the oven to 220°C/425°F/ gas 7. Boil the potatoes in their skins for 15 minutes. Run them under cold water until they are cool enough to handle and then peel them.
Grate the potatoes coarsely into a bowl and pour over the clarified butter. Season with salt and pepper, t