Preheat the oven to 180'C.
Peel the potatoes and slice into 2mm thick slices using a mandoline or sharp knife. Peel and finely dice the garlic. Chop the chestnuts.
In a large saucepan, bring the milk and double cream to the boil. Stir in the garlic and cook for one minute. Add the potatoes to the pan and season with salt. Bring back to the boil and remove the potatoes from the pan using a slotted spoon, then place in a deep baking tray. Sprinkle chestnuts between the layers of potatoes. Pour over any remaining cream, then place the tray in the oven and cook for 40 minutes until the top is golden brown. Check the potatoes are cooked using a skewer.
Peel and dice the shallot and garlic clove.
Heat a frying pan and melt the butter. Then cook the shallot, pink peppercorn, garlic and thyme
until golden in colour. Add the vegetable stock and reduce to nothing. Then add the cream and bring to the boil.
Preheat the oven to 200'C.
Slice the ceps.
Heat a frying pan and add the butter. Cook the ceps and leave to a side to cool.
Peel the Jerusalem artichoke. Drizzle with oil and sprinkle with salt, then roast in the oven until
soft and cooked through. Allow to cool.
Place few slices of ceps and artichokes on one circle of puff pastry. Brush the edges with egg yolk. Place the other circle of puff pastry on top and crimp the edges with a fork to seal.
Brush the pithiviers with any remaining egg yolk. Bake in the oven for 14 minutes or until golden brown.
«You can vary the flavour of the pithivier by using different kinds of roasted vegetables as the filling. »