Directions

1. Preheat oven to 450 degrees. Using a food processor with a slicing blade or a sharp knife, slice potatoes as thinly as possible, 1/4 inch thick or thinner. (Do not place sliced potatoes in water; the starch is needed to bind the layers.).
2. Brush bottom of a 10-inch cast-iron skillet with 1 1/2 tablespoons butter. Starting in center of pan, arrange potato slices, slightly overlapping, in circular pattern, covering surface. Brush with another 1 1/2 tablespoons butter; season well with salt and pepper. Repeat for two more layers.
3. Place over high heat until butter in pan sizzles, 2 to 4 minutes.
4. Transfer to oven; bake until potatoes are fork-tender, about 1 hour. Remove from oven. Run a small spatula around edges of potatoes; slide large spatula underneath potatoes to loosen. Carefully invert onto a plate, and cut into wedges.