Leek and Parmigiano Reggiano tart

Slice and rinse the leeks. Melt the butter in a large saucepan and add the leeks, salt and thyme leaves. Stir together, cover with a lid and cook over a gentle heat for 15-20 minutes, stirring occasionally, until the leeks are soft but not brown. Add the wine and bubble, without a lid, for 5-10 minutes until most of the liquid has evaporated. Remove from the heat and set aside.

Meanwhile, on a lightly floured surface, roll out the pastry to the thickness of a £1 coin and large enough to line a 23cm, loose- bottomed round tart tin. Ease into the tin, making sure to press it into the tin and up the edges, then trim so it overhangs the top by a finger’s width. Prick the base all over with a fork, line with a circle of baking parchment and chill for 30 minutes. Put a flat baking sheet in the oven and preheat to 180?C, gas mark 4.

Fill the parchment generously with ceramic baking beans or uncooked dried beans or rice*. Place on the baking sheet and bake for 20-25 minutes, until the sides have set and are light golden. Remove the parchment and beans, then bake for 10-15 minutes more until the base is pale golden. Remove from the oven and trim off the overhanging edge with a sharp serrated knife; brush out any crumbs from the inside of the case.

In a mixing bowl, beat together the cream, egg, yolks and cheese. Stir in the leek mixture and season if needed. Pour into the tart case and return to the oven for 25-30 minutes, or until just set in the middle and tinged with gold. Cool for 20 minutes before carefully removing the tart ring. Serve warm or at room temperature.