Leek and Gruyère cheese tart

1. Roll out pastry and line a greased 25 x 8 cm loose-bottomed tin. Prick the pastry base with a fork and fill with cooking beans (to bake blind). Chill for 10 minutes. Bake in preheated 220 ºC oven for 20 minutes, then remove the beans. Reduce oven temperature to 180 ºC. Return the case to the oven and continue to cook until pastry is crisp – start checking after 10 minutes, then at five-minute intervals. Remove from oven and reduce oven temperature to 130 ºC.
2. Cook leeks over a gentle heat in the butter until tender. Drain well.
3. Mix leeks with 75 g Gruyére and place in pastry case. Cover with beaten egg, milk and cream mixture and top with remaining cheese. Bake for about 50 minutes. Allow to stand for 15 minutes before removing from tin. Serve warm with a salad.