To make the pastry, sift the flour into a large bowl. Add salt, sugar and stir well. Tear the butter with your fingers into the bowl and mix it with the flour mixture until it becomes crumbly.

Make a hole in the center and add the beaten yolks. Mix the dough by squishing it through your fingers until it becomes soft and smooth. Squishing instead of kneading will slow the formation of the gluten bond that will turn the pastry hard when cooked. Let the pastry sit in the fridge for half an hour, covered with a plastic wrap.

Remove the pastry from the fridge and flatten it with a rolling pin. Lay the flattened dough in the tray and fill it with the lemon jam or curd. Cook in a preheated oven at 190/200°C for about 40 minutes.

As the tart cools down, prepare the meringue. Whisk the egg whites with the sugar using an electric whisk. As it starts to set, add a little at a time the powdered sugar and keep whisking until it form very stiff peaks.

Put the meringue in a piping bag and decorate the pie. Put the tart back in the oven at 50/80°C for 15 minutes. Broil it for 3 minutes to golden the merengue on top of the tarte. Serve it cool.