In a bowl, sift the flour; add sugars, butter, salt, and lemon zest;
Combine until the dough looks grainy; add egg yolk and water; continue to knead;
When the dough is set, shape it into a ball;
Flatten into a thick disc;
Preheat the oven, 180°C;
Roll the dough until large enough to fit a shallow pie tin;The recipe is given for a 25cm (10 inch) pie tin.
Grease a shallow pie tin; Line it with the pastry; refrigerate for 15 minutes; trim edge;
Use cooking parchment to line the pastry and use baking beads, cooking chain; Use rice if you don't have baking beads or cooking chain;
Bake for 10 minutes; Remove beads and paper; Cook for a further 10 minutes until the pastry is lightly golden;
Lemon Filling
Squeeze the lemons;
Whisk the eggs and the egg yolks with the sugar;
In a saucepan, slowly heat the mixture and pour the lemon juice and water; Whisk continually and add the cornflour, and butter;
When the mixture begins to thicken, stop heating; Leave it to chill for a few minutes;
Pour the lemon filling into the pastry; Bake for 8-10 minutes;Refrigerate to chill before decorating with topping;
Meringue Topping
Beat the egg whites, add the sugars gradually;
Put the meringue into a piping bag;
Decorate with meringue:You can spread with meringue to cover if you don't want to use a piping bag;Grill quickly to brown the meringue, or use a blowpipe kitchen torch;Enjoy!