Put the flour and salt in a mixing bowl. Add the butter and rub in with your fingertips until the mixture resembles fine breadcrumbs.
Stir in the icing sugar and gradually work in the egg yolks and water to make a firm dough.
Knead the dough briefly on a lightly floured surface, then cover with clingfilm and chill for 30 minutes. Roll out the dough and use to line a 25 cm (10 inch) fluted pie dish or tart tin. Prick the pastry case with a fork and chill for 20 minutes.
Line the pastry case with baking paper and ceramic baking beans and bake in a preheated oven, 200°C (400°F), Gas Mark 6, for 10 minutes. Remove the paper and beans and bake for a further 10 minutes until crisp and golden. Remove from the oven and reduce the temperature to 150°C (300°F), Gas Mark 2.
Beat together all the filling ingredients, pour them into the pastry case, and bake for 20–25 minutes, or until the filling is just set. Let the tart cool completely, dust with sifted icing sugar and serve.