Sift the flour, icing sugar & salt into a large mixing bowl.
Add the butter into the flour then rub in with your fingers until the mix resembles breadcrumbs with some large pieces of butter still visible.
Stir together the 30g of egg yolks & the vanilla then add to the flour.
Mix together until the pastry starts to come together then tip out onto a clean worksurface & gently knead until you have a smooth dough (be careful not to overwork).Flatten into a disc, wrap in clingfilm & chill in the fridge for at least 2 hours. Next, place the chilled pastry onto a lightly floured worksurface & roll out to a thickness of 3mm-4mm.Pick the pastry up using a rolling pin, drape over the tart tin & carefully mould into the tin. Using some of the overhanging pastry, rolled into a ball to press the pastry into the sides of the tin works best. Roll your rolling pin across the top of the tin to trim the pastry case then prick the base with a fork. Chill in the fridge for a minimum of 1 hour but overnight is best.
Preheat an oven to 170°c/150°c fan (340°f/300°f).
Make a large cartouche out of baking parchment, scrunch it up then place inside your pastry case. Fill the parchment with baking beans then bake in the preheated oven for 15-20 minutes or until the top of the pastry case is starting to turn golden brown & the edges have set.
Remove the baking beans & parchment & return the case to the oven & cook until the case is a light golden brown all over, roughly 5-10 minutes.
Brush the base of the cooked case with the beaten egg yolk & cook for another 2-3 minutes – this will seal any holes in the pastry & prevents the filling from leaking.
Remove the pastry case from the oven & set aside while you make the filling.