Chicken, mushroom and wild garlic pie

Sift the flour, xanthan gum and salt into a large bowl and stir to combine.

Grate the chilled butter into the bowl (use the large grater setting on a cheese grater) and toss the butter strands through the flour with a fork. Once the butter is coated with flour, use your fingertips to rub the butter into the flour until you have a coarse breadcrumb-like texture. Add the beaten eggs and stir through with the fork.

Add 4 tbsp water (you may not need the rest, depending on your flour blend) and use your hands to bring the ingredients together to form a ball of dough. It should come away from the sides of the bowl and the dough should be smooth and pliable. If it is still a bit crumbly, add an extra tablespoon of water (and a second if needed) and work to combine.

Transfer the dough to a large piece of baking parchment, about 40cm (16in) long. Press it down gently with your hands to form an oval shape, about 2cm (¾in) thick. Fold the paper over to cover the other side of the dough, then fold the edges over to form a parcel. Leave to chill in the refrigerator for 30 minutes.

Add the onion and carrot to a large non-stick saucepan with a drizzle of olive oil and cook over a low-medium heat for 10 minutes, or until the onion has softened.

Rinse the wild garlic leaves very well, then add to a heatproof bowl and cover with boiling water. Leave for 1 minute, then drain and rinse in cold water to stop them cooking further. Squeeze any excess water out of the leaves and set aside. If using spinach and garlic instead, do this with the spinach leaves and add the garlic to the pan with the onion.

Add the mushrooms to the pan with the onion and carrot and cook for 5 minutes, or until the mushrooms have softened and any excess liquid has evaporated.

Add the chicken to the pan, then turn off the heat. Simply stir through (no cooking needed, you don’t want to dry out the chicken), then tip the contents of the pan into a large bowl and set aside.

Add the butter and cornflour to the pan and heat over a medium heat until the butter is melted. Use a small whisk or wooden spoon to mix the butter and flour into a roux (a thick paste) and sizzle for a minute.

Add the mustard, then the stock and wine in stages, pouring a little in at a time, stirring constantly and keeping the pan over the heat. At each addition, stir the stock and wine into the roux, then whisk or stir quite vigorously to ensure that the sauce remains smooth and lump free. Add the cream and milk and whisk again until you have a thick, smooth sauce (if not thick yet, keep heating and stirring to thicken – if it’s a bit lumpy, don’t fret, stir well, but no one will notice any little lumps in the final dish).

Tip the chicken and mushroom mix into the sauce and stir well to combine. Roughly chop the wild garlic leaf ball (or spinach) so it’s quite fine, then stir through the sauce. Set aside.

Preheat the oven to 180°C/Gas Mark 4. Grease a 23cm (9in) springform tin well with butter. Unwrap the chilled dough and place the paper on the work surface – don’t flour. Using a rolling pin, roll the pastry out quite thin, about 4mm (¼in) thick, in a large circular shape, wide enough to completely cover the tin and sides. The pastry shouldn’t stick to your rolling pin, but if it does, place a large piece of clingfilm, about 30cm (12in), on top of the dough and roll on top of it.

Peel off the clingfilm, if using, and gently flip the paper and dough over onto the prepared tin, then carefully peel the paper off. Tuck the pastry into the tin, pressing down gently to completely cover the base and get it into the base of the tin. Bring the pastry to the top of the tin and use a sharp knife to slice off the excess dough. Any breaks in the pastry can be easily patched, just press the dough back together and ensure it is well sealed. Set the offcuts aside as you’ll use these to make the pie lid.

Tip the pie filling into the tin, levelling it on top, ensuring that you have a gap of 2cm (¾in) of pastry above the top of the filling.

Roll the remaining pastry out into a circular pie lid shape and arrange on top of the filling. Cut off any excess, then gently press round the edge with your fingertip to seal the sides and lid, before crimping with a fork. Cut a small cross in the centre to allow any steam to escape during cooking, then decorate the pie as you wish – adding pastry leaves, flowers or other shapes made with the pastry offcuts, or laying wild garlic leaves or flowers on top.

For the egg wash, whisk the egg and milk together in a small bowl, then lightly brush over the top. Bake the pie in the oven for 50 minutes. Carefully ease out of the tin and either enjoy straight away or it will stay quite warm for an hour or so after cooking.

You can use a different size springform pan or pie tin if you wish, but if using a pie dish please make sure it is deep, so as to hold a good amount of filling. This is a big pie.