First make the pastry, in a food-processor, mixer or by hand, cream together the butter and icing sugar until they are light and fluffy.
Add the egg yolks, mix well, then fold in the flour. Press the dough into a ball and refrigerate it for a couple of hours.
On a floured table, roll cat the pastry to about ½ cm think.
Grease and line a 22-24 cm x 4-5 cm deep flan ring a