Prepare the pastry: combine the flour, salt and butter in a mixer until the mixture resembles coarse breadcrumbs. Add icing sugar followed by the egg yolks, and mix until well combined. Wrap the dough and let it cool in the fridge for at least one hour.

Preheat the oven to 165°. Place the dough, in large pieces, in a 30cm loose-bottomed fluted flan dish, then press it evenly over the sides and the bottom. Allow to rest for 15 minutes.

Line the dough with baking parchment and cover with uncooked rice or beans. Bake for 20 minutes or until lightly golden. Remove it from the oven, remove the paper and the rice and bake for a further 10 minutes, or until golden brown. Let it cool.

Meanwhile, prepare the filling. Put the remaining ingredients, except the butter, in a large saucepan on a very low heat; whisk until the eggs have broken up and the sugar has dissolved.

Soften two sticks and 5 tablespoons of unsalted butter. Add half the butter and keep whisking. As the eggs begin to cook, the mixture will thicken enough to coat the back of a spoon. Add the rest of the butter and keep whisking until the mixture is very thick. Keep whisking throughout the cooking process to prevent it from curdling.

Soften two sticks and 5 tablespoons of unsalted butter. Add half the butter and keep whisking. As the eggs begin to cook, the mixture will thicken enough to coat the back of a spoon. Add the rest of the butter and keep whisking until the mixture is very thick. Keep whisking throughout the cooking process to prevent it from curdling.