Preheat your oven to 220°C (425°F) and position a rack in the center.
Peel (optional) and very thinly slice the Waxy Potatoes — about 1–2 mm thick — using a mandoline or a very sharp knife. Rinse briefly to remove excess starch and pat thoroughly dry with a kitchen towel.
Gently warm and melt the Clarified Unsalted Butter in a small saucepan or microwave until fluid; keep some aside for brushing during assembly.
Lightly brush a heavy ovenproof skillet or round baking dish with some of the melted butter to coat the bottom and sides.
Arrange the potato slices in concentric overlapping circles in the dish, building up even layers. After completing each layer (or every 3–4 layers), brush liberally with melted butter and season lightly with Sea Salt and freshly ground Black Pepper. Continue until the dish is filled or you’ve used the potatoes.
Press the assembled stack firmly with the back of a spoon or a small plate to compact the layers. Cover the top with a piece of parchment paper and place an ovenproof weight (a smaller skillet or a foil-wrapped brick) on top if you have one.
Bake, weighted and covered, for about 35–45 minutes, or until the bottom is set and beginning to brown. Remove the weight and parchment for the final browning.
Return the dish to the oven and bake an additional 10–15 minutes, or until the top is deeply golden and the edges are crisp.
Let the Pommes Anna rest for 5 minutes, then carefully invert onto a serving plate (use oven mitts and a plate large enough to catch any butter). If any parts need extra crisping, return the dish briefly to the oven or brown in a hot skillet.
Slice into wedges and serve immediately as an elegant, buttery accompaniment to meats or a simple green salad.
