A thin layer of crisp short pastry covered with a thin almond meringue is the perfect biscuit to serve with fruit or sorbets. The egg whites in the topping are boiled very briefly, which is unusual, but the recipe is quite safe!
Preheat the oven, placing a baking sheet in the centre. Sift the flour and icing sugar together. Cut the butter into small pieces, and, using your fingertips, rub it into the mixture until it resembles fine crumbs. Lightly mix in the egg yolk and lemon zest: a food processor can do all this very quickly if you have one. Grease a 23 X 32 cm (9 X 12-inch) shallow baking tin and line it with bakin