Making the biscuit pie shell:

1. Place the egg yolks in a bowl and whisk vigorously with the sugar until the mixture whitens and foams.
2. Incorporate the soft butter cut into cubes then add the flour, salt and baking powder.
3. Work everything to obtain a homogeneous and smooth dough. Form a ball, wrap it in cling film and place in the fridge for 30 minutes.
4. Preheat the oven to 180°C (th.6).
5. Roll out the dough to a thickness of about ½ cm then cut into disks using a cookie cutter.
6. Place them on a baking sheet covered with baking paper, put them in the oven and cook for about 20 minutes.
7. Let cool.

Making the lemon cream:

1. Take the zest of an untreated lemon. Bring the juice of the lemons with the zest to the boil.
2. Beat the eggs with the sugar and cornstarch. Gradually add the lemon juice in a stream without stopping whipping.
3. Put everything back on medium heat and thicken, stirring well all the time, you will obtain a cream.
4. Let cool and then add the soft butter in pieces, whisking well.
5. Garnish the precooked pie shell. Reserve in the fridge.

Optional finish, the meringue:

1. Whip the egg whites until stiff, add the sugar and whisk for a few more seconds.
2. Garnish the top of the tart with a pastry bag for example and switch to a hot oven ‘grill function’ for 1 minute to color the meringue or, to go faster, brown the meringue with a blowtorch.