Cholera Pie

Preheat the oven to 170°C. Boil the potatoes in salted water for 25 minutes until almost tender, let cool, peel and cut into roughly 2 cm cubes.

Slice the leek lengthwise, wash thoroughly and cut into 2–3 cm pieces. Blanch in boiling salted water for 3–5 minutes, then drain and rinse under cold water.

Thinly slice the onion. Melt half the butter and sauté the onion until soft, then transfer to a bowl.

Core the apples and cut into small pieces. In the same pan, melt the remaining butter and quickly sauté the apples, then add the leek and onion, season with salt and pepper.

Add the potatoes to the apple and vegetable mixture, stirring gently so the cubes don't break, and let the filling cool for 10 minutes. Grate the raclette on the coarse side of a grater.

Line a deep 28 cm tart tin with half of the puff pastry, then layer or spread the filling evenly, sprinkling with raclette as you go.

Cover the pie with the remaining pastry, seal the edges, cut a small vent in the centre to let steam escape, and brush the top with beaten egg.

Bake for 60 minutes at 170°C until golden brown. Let the pie rest for 10 minutes before slicing; serve warm with a green salad.