First, make the pastry. Tip the flours into a bowl and mix with the parmesan, thyme and cayenne pepper. Rub in the butter until it resembles breadcrumbs, then pour in 2-3 tbsp of cold water. Mix it in with a cutlery knife, then use your hands to bring together into a dough – you might need to add a bit more water. Knead the dough briefly until smooth, then split in half, press into two discs – one larger than the other – wrap in cling film, and refrigerate for 30 mins.

Meanwhile, put the leek, swede, milk, a large pinch of salt and the bay leaf in a pan and bring to the boil. Simmer for 10-15 mins until the swede is tender. Season with black pepper and nutmeg. Strain through a sieve, reserving the milk, and put the veg in a bowl. Using the same saucepan, melt the butter, then add the flour and cook for 2 mins. Slowly pour the milk back into the pan, whisking constantly to create a silky sauce. Stir in the cheddar and wine and stir until it’s melted, then remove from the heat and allow to cool for a couple of mins before adding 1 beaten egg and the mustard. Season and stir the veg into the mix.

Heat the oven to 200C/180C fan/gas 6. Butter and flour a 23cm pie dish. Roll the pastry out into two discs, using the large disc first to line the dish. Spoon in the filling, and brush a little of the sauce from the filling onto the edges of the pastry. Press the other disc on top and crimp the edges. Make two slits in the top of the pastry, brush with the remaining egg and bake for 30-35 mins until golden.