In a bowl, rub the cold cubed butter with the sugar and flour into a sandy texture, add the egg yolks, a pinch of salt and the lemon zest, and knead until a smooth ball of dough forms.

Wrap the dough in plastic film and let it rest in the refrigerator for 30 minutes.

Roll out the shortcrust dough to about 3mm thick and line a 20-25 cm tin, then leave it in the freezer for about an hour.

Whip the softened butter with the sugar, then add the beaten egg in a stream, followed by the flours and the lemon zest and juice, mixing well.

Spread a layer of the frangipane over the base of the shortcrust, about half the dose for a 20 cm tin.

Bake for 25-30 minutes at 170°C.

Mix the lemon juice with the sugar, eggs and cornstarch for the curd.

Cook over low heat, stirring continuously, until thickened.

Off the heat, stir in the rehydrated gelatine, mixing well.

Add the cold butter a little at a time, in pieces, along with the grated lemon zest, mixing.

Pour the curd over the cooled tart and let it set in the fridge.

In a small saucepan, make a syrup with the water and sugar for the Italian meringue.

When the syrup reaches 121°C, add it to the whipped egg whites and continue whipping until the meringue reaches room temperature.

Decorate with a piping bag fitted with a round nozzle and torch with a blowtorch.