This easy-to-follow recipe makes the most basic and the most delicious roesti.
Melt the butter or half butter with half olive oil in a 10-inch nonstick skillet over medium heat.
Season the shredded potatoes with the salt and black pepper to taste.
Spread the potatoes evenly in the skillet.
Press with the spatula to form a big pancake.
Cook until the bottom crust becomes golden and brown, 14 to 16 minutes.
Press the potatoes with the spatula about three times during the cooking.
Shake the pan or loosen the roesti with the spatula.
Place a large plate over the skillet, and carefully invert.
Return the roesti to the pan by sliding the plate.
Continue to cook until the now-bottom crust turns golden brown as well, about 12 minutes.
Serve warm with sour cream if needed.