Steps
- Preheat the oven to 400°F / 200°C. Melt 150g of unsalted butter over low heat, skimming off white foam. Brush the base and sides of an 8in / 20cm ovenproof skillet generously.
- Peel 1.6kg of starchy potatoes and slice 1⁄16in / 2mm thick. Rinse in three changes of cold water, drain, and pat dry.
- Layer overlapping potato circles in the skillet, brushing each layer with butter and seasoning with sea salt. Cook over low heat for 10 minutes, until the base browns.
- Butter an 11in / 28cm parchment circle and place butter-side down on the potatoes. Set a smaller ovenproof dish filled with baking weights on top.
- Bake for 25 minutes. Remove the weights and parchment, then bake for 20 minutes more, until a skewer slides easily through. Turn onto a plate and cut into wedges.