Leek and Potato Galette

Preheat oven to 375 degrees, with rack set in top third. Line bottom of a 9-inch cake pan with a round of parchment paper. Place melted butter in a large bowl. Using a mandoline or cutting by hand, slice the potatoes 1/8 inch thick; add to bowl with butter. Season with salt and pepper, and toss to coat. In prepared pan, arrange some of the potatoes around edge of pan, overlapping the slices.

Fill center of pan with more overlapping slices. Sprinkle with half the leek and half the cheese; season with salt and pepper. Repeat with another layer of potatoes and remaining leek and cheese; season with salt and pepper. Top with remaining potatoes. Using a spatula, press galette down firmly.

Bake until potatoes are tender, 70 to 80 minutes, pressing down firmly twice with a spatula during cooking. Run knife around edge of pan. Carefully invert galette onto a plate, remove parchment, and reinvert onto serving plate. Cut into wedges, and serve.