Preheat the oven to 500°.

Thinly slice the potatoes about 1/8-inch thick and wash them thoroughly in cold running water. Drain and place them in a bowl lightly salted ice water for up to 1 hour. Drain and thoroughly dry the slices with paper towels.

Coat the pie pan with 3 tablespoons of the butter. Arrange the potatoes in an overlapping spiral on the bottom of the pan. Season the first layer with salt and pepper and coat with butter. Continue making layers, alternating potatoes, seasonings, and butter and ending with a layer of potatoes, until the pan is filled.

Place a clean kitchen towel over the pan and weigh down with a second pan or baking sheet and a heavy weight for 10 minutes. Remove the weights, pan, and towel and coat the tart with the remaining butter.

Bake for 45 minutes, or until the bottom crust is golden. Let the tart rest for 5 minutes.

Place a serving platter over the tart and invert. If the potatoes do not immediately release, run a metal spatula around the rim of the pan. Slice into pie wedges and serve hot.