The test kitchen prefers a roesti prepared with potatoes that have been cut through the large shredding disk of a food processor. It is possible to use a box grater to cut the potatoes, but they should be cut lengthwise, so you are left with long shreds. It is imperative to squeeze the potatoes as dry as possible. A well-seasoned cast-iron skillet can be used in place of the nonstick skillet. By adding fried eggs, ham, bacon, cheese, cooked onions, and/or tomatoes, roesti can be turned into a light meal (see below).

Directions
1. Place potatoes in large bowl and fill with cold water. Using hands, swirl to remove excess starch, then drain in strainer.

2. Wipe bowl dry. Place half of potatoes in center of kitchen towel. Gather ends together and twist as tightly as possible to expel maximum moisture. Transfer potatoes to bowl and repeat process with remaining potatoes.

3. Sprinkle salt, cornstarch, and pepper to taste over potatoes. Using hands or fork, toss ingredients together until well blended.

4. Melt 2 tablespoons butter in 10-inch nonstick skillet over medium heat. When foaming subsides, add potato mixture and spread into even layer. Cover and cook 6 minutes. Remove cover and, using spatula, gently press potatoes down to form round cake. Cook, occasionally pressing on potatoes to shape into uniform round cake, until bottom is deep golden brown, 4 to 6 minutes longer.

5. Shake skillet to loosen roesti and slide onto large plate. Add remaining 2 tablespoons butter to skillet and swirl to coat pan. Invert roesti onto second plate and slide it, browned side up, back into skillet. Cook, occasionally pressing down on cake, until bottom is well browned, 7 to 9 minutes. Remove pan from heat and allow cake to cool in pan for 5 minutes. Transfer roesti to cutting board, cut into 4 pieces, and serve immediately.

Follow recipe for Potato Roesti, increasing amount of potatoes to 21/2 pounds. Squeeze potatoes in 3 batches (instead of 2) and increase salt to 3/4 teaspoon and cornstarch to 11/2 teaspoons. Cook roesti in 12-inch nonstick skillet, adding additional 1/2 tablespoon butter per side (5 tablespoons total). Increase uncovered cooking time in step 4 to 8 to 10 minutes and cooking time in step 5 to 8 to 10 minutes.