Heat 25g of the butter in a frying pan over a medium heat until sizzling, add the wild garlic leaves, season with salt and cook for 5 mins until completely wilted and soft. Leave to cool, then tip onto a board, roughly chop and set aside.

Melt the rest of butter in a frying pan over a medium heat. Tip in the leeks and chicken, season and cook for 10-12 mins until the chicken is just cooked and the leeks have softened. Stir in the flour and cook for 3 mins until the mix resembles a sandy paste. Pour in the wine and bubble for 1-2 mins until reduced by half, then add the stock and crème fraîche, bring to a simmer and cook for 10 mins more until the chicken is cooked through. Stir through the cooked wild garlic and simmer for another 2-3 mins until thick and creamy. Season to taste, remove from the heat and, if you have any wild garlic stalks, finely slice them and stir through. Leave to cool completely, tip into a container and chill for 2 hrs, or overnight. Will keep chilled for up to two days.

To make the pastry, rub the butter into the flour with a large pinch of salt using your fingertips until completely combined. Add half the beaten egg and 3 tbsp ice-cold water, and bring together into a dough using your hands, adding a little more water, 1 tbsp at a time, until you have a dough that’s soft enough to work with. Knead for a minute so it completely comes together, then chill for 1 hr. Will keep chilled for two days.

Butter a 23cm pie tin. Remove the pastry from the fridge and allow it to come to room temperature, then divide into three. On a floured surface, roll out two-thirds of the pastry until it’s the thickness of a £1 coin and large enough to line the tin with some overhanging. Use it to line the tin, then spoon in the filling. Roll out the remaining pastry into a rough 25cm roughly circle. Brush the edge of the pastry with a little of the remaining beaten egg, then drape over the filling. Trim the edge, then crimp or press with a fork to seal the edges and use any pastry trimmings to decorate, if you like Chill until you’re ready to cook. Will keep chilled for up to 24 hrs.

Heat the oven to 220C/200C fan/gas 7 with a baking sheet inside. Brush the pie with some of the remaining beaten egg then, using a sharp knife, lightly score a criss-cross pattern on top. Put on the hot baking sheet and bake for 20 mins, then brush with the rest of the egg, season with sea salt and bake for another 15-20 mins until deep golden. Remove from the oven, leave to rest for 10 mins, then carefully remove from the tin, put on a serving board and cut into wedges to serve.