Hull and halve strawberries, sprinkle over some caster sugar and leave to macerate for an hour or so.
Roll out puff pastry into a rectangle, and with a sharp knife trim off a cm or so from around the edges,
wet the remaining edge and place the strips back onto the pastry to build a little wall. Sprinkle the wall
with granulated sugar. Prick the centre all over with a fork and bake in a 180°C oven for 25 minutes, until
nicely puffed and golden. Let cool. Meanwhile, make some crème pâtissière, as follows: heat 200 ml whole milk
with a tsp vanilla extract. Beat together 2 egg yolks, 40 g caster sugar and 2 Tbs cornflour, then gradually
beat in the hot milk. When it is all smooth, return to the pan and bring to a gentle simmer, stirring, until
well thickened. Remove from the heat and beat in a Tbs butter. Let this cool completely, then spread onto
the cooled cooked pastry tart. Cover with the strawberries.