Deep celeriac, potato and Gruyère pie

Serves 6-8 Starters and mains

Advertisement

Method

To make the filling, put the porcini in a heatproof bowl, cover with 250ml boiling water and set aside.

Cut off the gnarly top and bottom of the celeriac. Peel the remaining celeriac, halve and cut into slices approx. 1cm thick. Bring a pan of salted water to the boil, add the celeriac and cook for 15–20 minutes until just tender. Cut the potatoes into slices about 1.5cm thick and simmer in a separate pan of boiling salted water until tender. Drain the vegetables and season while warm, then set aside.

Heat the butter and oil in a large pan over a medium heat, then add the onions and cook until just softening. Add the rosemary leaves and, when the onions are soft, add the mushrooms. Lift the now-rehydrated porcini out of the water, reserving the water, roughly chop them and add to the pan. Cook for 5 minutes, then pour in the porcini soaking water. Stir and remove the pan from the heat.

Peel, quarter and core the apple, then dice and add to the pan of mushrooms. Cut the cooked celeriac and potato slices into roughly 1cm cubes, add to the onion and mushroom mix, stir in the crème fraîche and season generously with salt and ground pepper.

If making in advance, the filling will keep in the fridge for up to a day, but return to room temperature before building the pie.

To make the pie, preheat the oven to 190C/170C F/Gas 5 with a large baking tray inside to get hot. Use a little of the butter or lard to grease the base and sides of your tin.

To make the pastry, sift the flours and salt into a large mixing bowl, making a well in the middle. Cut the butter or lard into pieces into a pan and add 180ml water if using butter or 200ml if using lard. Put the pan over a medium heat and as soon as the fat/water mix is bubbling fast, pour it into the flour bowl. Stir together using a wooden spoon to form a dough and then use your hands. It won’t need much kneading.

Separate off two-thirds of the dough. Roll it out on a lightly- floured worktop to a thickness of around 4mm and cut out a circle that covers the base of a deep 22cm springform cake tin. Lift the dough over and into the base, preferably going a little way up the sides of the tin. Use more dough to roll pieces for the sides of the pie – you can patch up and press pieces together if necessary.

Spoon in about a third of the filling mix, then scatter over half the grated Gruyère. Repeat with another third of filling, the rest of the cheese, and finally the last of the celeriac/potato mix.

Take most of the remaining pastry and roll out to form a lid. Lift it on to the pie and bring the side pastry up and over the edges and press together, so you are building your pie to sit inside and below the top of the tin, crimping if you like.

The last of the pastry can be used to make decorations such as stars or leaves cut out with biscuit cutters before pressing them on top.

Push the handle of a wooden spoon through the centre of the pie’s lid to make a steam hole. Beat the egg with a little water and brush over the pastry.

Put the pie on the hot baking tray and bake for 45 minutes. Lift it out and gently release and remove the springform ring, then return to the oven for 15–20 minutes so the pastry sides can brown a little too. It is ready when the pastry is golden on top.

Let the pie sit out of the oven for 5–10 minutes before slicing and serve while still warm, with the greens alongside.