2 1/2 cups plain flour
Pinch sea salt
1 cup cold, unsalted butter, cut into cubes
3/4 cup icing sugar, sifted
3 egg yolks
7 lemons, juice and zest finely grated
1 1/2 cups white sugar
6 whole eggs
9 egg yolks
1 1/4 cups unsalted butter at room temperature
Put flour, salt and butter into food processor until it resembles coarse breadcrumbs.
Add sugar, egg yolks and pulse.
Remove pastry and wrap in plastic, place in refrigerator for 1 1/2 hours.
Pre-heat oven to 320 F.
Spray fluted tart pan with canola oil, or use non-stick loose-bottomed fluted tart pan.
Roll our pastry and press firmly into tart pan. Put in the fridge for 15 minutes.
Remove and bake for 25 minutes or until golden brown. Let cool.
Put zest, lemon juice, sugar, eggs and yolks into a large saucepan. Place over very low heat and whisk until eggs have broken and sugar has dissolved.
Add only half the butter and continue to whisk. The eggs will start to cook and the mixture should thicken up. Keep whisking and add remaining butter, until it becomes very thick.
Take off the heat, but continue to whisk until lukewarm.
Gently spoon filling into tart pan and let it settle for at least 10 minutes.
Grill in oven for a few minutes until brown, or use a baker’s blowtorch.
Allow to cool for one hour and then refrigerate.
Serve with a dollop of thickened cream or mascarpone.