Serves 3 to 4

1Pour 200ml of boiling water into a bowl and add the dried mushrooms. Leave to soak for 20 minutes. Melt the butter in a sauté pan, add the shallots and cook over a low heat until they are golden. Add the king oyster mushrooms and cook until soft — they will release a little liquid, which will mostly evaporate.

2Strain the dried wild mushrooms, discarding the liquid, and squeeze any excess water out of them. Chop them and add to the pan. Add the marsala and turn up the heat. Cook, stirring, until all the liquor evaporates. Stir in the cream, season to taste, and cook for 30 seconds more. Remove from the heat and set to one side.

3Heat the duck fat in a heavy-based frying pan until it begins to smoke. Sear the venison fillets very briefly on all sides and immediately remove them. Set aside to cool. Make a little extra juice for serving, adding the stock and marsala to the meat pan and reducing by boiling down to one-third. Set aside to reheat for serving.

4Preheat the oven to 200°C/ gas mark 6. Roll the pastry into rectangles, 3mm thick — you will have quite a bit of excess. Cut each piece into two, so you have four rectangles. Lay two of the pieces on a baking tray lined with baking parchment. Spoon one quarter of the mushroom mixture in the centre of each, spreading it to an area that will accommodate the fillet — about 8cm by 15cm.

5Place a piece of venison fillet on each — or two pieces if you used medallions, as I did. Spoon the remaining mushroom mixture on to each of the pies, pressing it down gently. If the mixture spills on to the surrounding pastry, brush it off with a spatula and add to the heap on top of the fillets. Brush the area around the mushroom and venison heap with water.

6Next, lay another piece of pastry over each, very gently bringing it down around the pie contents, pressing around the edges, to make a dome. Leaving a 2cm rim of pastry, cut around the edge of the pithivier and repeat with the second one.

7Brush both with beaten egg. Very lightly — so as not to pierce the pastry — score the pies with light cuts from top to bottom (see image). Finally, cut a little central hole in the top. At this point you can refrigerate the pithiviers, ready to bake the following day.

8Bake for 20 minutes until beautifully golden, then remove from the oven and allow to rest for 5 minutes before serving. Reheat the juice and strain into a gravy jug, ready to serve. Slice each pithivier into four with a very sharp carving knife, once you have taken them to the table in all their glory. Serve with a creamy celeriac purée, perhaps some braised red cabbage or steamed kale.