1/2 cup clarified butter, plus more as needed
2 lb. red-skinned potatoes, peeled and
cut into 1/8-inch-thick slices
Salt and freshly ground pepper, to taste
Preheat an oven to 425°F. Brush an 8 1/2-inch tapas pan with 2 Tbs. of the clarified butter.
Place 1 potato slice in the center of the pan and cover the bottom with concentric circles of potato slices, slightly overlapping. Line the sides of the pan with potato slices, slightly overlapping. Season with salt and pepper and drizzle with 1 Tbs. of the butter. Repeat with the remaining ingredients to form about 4 layers. Cover the pan tightly with a piece of buttered aluminum foil.
Set the pan over medium heat and cook until the potatoes sizzle, 1 to 2 minutes. Transfer the pan to the oven and bake for 30 minutes. Remove the foil and press down on the potatoes with the back of a spatula. Bake until the potatoes are golden brown, about 30 minutes more.
Run a knife around the inside of the pan. Press a plate against the potatoes and carefully tilt the pan over a bowl to catch the excess butter. Invert the potato cake onto the plate and cut into 6 wedges. Serve immediately.