Potato, olive and goat's cheese pie

Put the leeks, butter and thyme in a pan, cover and cook over a low heat for about 20 minutes until very soft, stirring occasionally.

While the leeks are cooking, put the potatoes in a pan of cold water, bring to the boil and simmer for 5 minutes until just cooked.

Drain the potatoes and stir into the cooked leeks then add the olives.

Leave to cool, stir in the goat's cheese and season with sea salt and plenty of black pepper. Add the marjoram leaves.

Heat the oven to 200 C / Fan 180 C / Gas 6.

Divide the pastry in two and roll one of the pieces to the size of a dinner plate. Transfer this to a baking tray and roll the remaining pastry and any trimmings to around about 5cm bigger than the first.

Pile the filling into the middle of the round on the baking sheet, leaving a 4cm border. Brush the border with the beaten egg, then drape over the larger piece of pastry. Trim the edges to neaten, then press the sides together with your thumb. Brush the pie all over with egg.

Bake for 35 to 40 minutes until golden. Leave to rest for 10 minutes before cutting into wedges.