Ingredients

Step by step

1. Heat a frying pan over a medium heat, then add the oil. When hot, add the leeks and onion, and sauté for 2 minutes. Add the garlic and sauté until the leeks and onion are softened but not coloured, and any excess liquid has evaporated. Season with salt and pepper.
2. Sprinkle over the flour and stir for 1-2 minutes, then slowly stir in the stock. Add the ham, crème fraîche and mustard, and stir together. Adjust the seasoning, if necessary. Set aside to cool.
3. Roll out the pastry on a lightly floured surface with a flour-dusted rolling pin until it is about 2-3mm thick. Cut a strip of pastry the same width as the rim of a pie dish (about 1.7 litre capacity). Lightly brush the edge of the dish with a little of the beaten egg yolk and fix the strip around it. Spoon the filling into the pie dish.
4. Brush the top of the pastry strip with egg yolk, then lay over the remaining pastry, press down lightly and crimp the edge. Cut off the excess pastry to trim the edge. Use a small knife to cut a steam hole in the centre, then insert a small funnel made from foil to release the steam while baking. Leave the pie to chill for at least 20 minutes before baking. Meanwhile, preheat the oven to 220°C, fan 200°C, gas 7.
5. When you’re ready to bake the pie, brush the surface with egg yolk. Place the pie on a baking sheet and bake for 35-45 minutes, or until the filling is piping hot and the pastry is well-risen and golden brown. Set aside to rest for 5 minutes before serving.