This version of the traditional Swiss pancake can seem a bit daunting to make, but after a little practice, these potato cakes will become a permanent part of your weekend repertoire. Use russet (baking) potatoes and take the time to drain them as much as possible so the final cakes have a good texture. The quantity here makes 4 thin roesti; use 2 skillets at once, if you have them, and keep the bowl covered with plastic wrap to prevent the potatoes from discoloring. As you make the pancakes, keep them in a 300-degree oven to stay warm. To make ahead, let the roesti cool to room temperature; reheat them on a rimmed baking sheet in a 350-degree oven for 10 to 15 minutes before serving.