Ham, leek and potato pie

Method

1. Make the pastry (it will help if your kitchen isn’t too hot). Using the foil to stop your fingers touching the butter, coarsely grate it into a large mixing bowl straight from the freezer. Work quickly to keep it as cold as possible.
2. Sift over the flour with a couple of pinches of salt, then sprinkle over 2 tbsp chilled water and mix witha palette knife or dinner knife to a rough dough. Add a little more water if needed to bring it together, then tip out onto a lightly floured work surface and shape it into a disc with your hands. Handle it as little as possible. The pastry should still have visible flecks of butter through it. Wrap in cling film, then chill.
3. To make the filling, put the potatoes into a pan of boiling water and cook for around 5 minutes or until not quite done. Drain and leave to steam dry in the colander for a few minutes. Melt the butter in a large sauté pan or saucepan, then add the leeks with some salt. Cook, stirring, for around 5 minutes or until softened but not coloured, then stir in the mace and flour until the leeks are evenly coated. Cook,stirring often, for 2-3 minutes until the flour starts to smell biscuitty. Stir in the mustard and add the bay leaves. Gradually, over a medium-high heat and stirring all the time, add the chicken stock. It will thicken as it cooks. It should be thick enough to thickly coat the back of a spoon – if it looks too thin, stop adding stock and let it bubble and thicken while stirring, then continue adding stock.
4. Once all the stock has been added and the sauce is the right thickness, stir through the cream and bubble for a minute or so. Stir through the potatoes and the ham, then taste it – you probably won’t need to add salt but it will need some pepper. Transfer to a 1.5 litre ovenproof pie dish and leave to cool completely, loosely covered with cling film.
5. Once the filling has cooled, heat the oven to 200°C/fan180°C/gas 6. Remove the pastry from the fridge and, on a floured work surface, roll out to around 0.5cm thick. Brush the rim of the pie dish with a little water. Drape the pastry around the rolling pin, unroll it over the pie dish, then trim excess pastry from the edges. Gather it up and re-roll to cut out decorations for the top, if you like.
6. Seal the pastry onto the pie dish by pressing lightly around the edges (use a fork if you want to make it more decorative), then cut a steam hole in the top and decorate with the trimmings if you want to. Brush all over with beaten egg, then freeze the pie for 5 minutes to harden the pastry. Bake in the top third of the oven for 30-35 minutes until the pastry is golden and crisp and the centre is piping hot. To test this, push a skewer into the middle of the pie and keep it there for 15 seconds. If the skewer feels hot, the pie will be ready. Leave for 10 minutes, then serve with steamed greens.