Roll out the puff pastry until it fits a 9-inch (23cm) springform pan, leaving some overhang. Press it into the base and up the sides, creating a neat edge. Chill in the freezer for 30 minutes.

Preheat your oven to 190°C (375°F). Line the chilled pastry with baking paper and fill it with baking beads.

Bake for 15 minutes until the edges are golden.

Remove the baking beads and paper, then return the crust to the oven for 5-10 more minutes until lightly golden. Let it cool completely.

In a saucepan, heat the milk and cream with the vanilla bean until it steams. Remove from heat and let it sit for 10 minutes to infuse flavors.

In a large bowl, whisk together the egg yolks, sugar, and cornstarch until pale and smooth.

Slowly pour the warm milk mixture into the egg mixture, whisking constantly to prevent curdling.

Pour the mixture back into the saucepan and cook over medium heat, whisking until it thickens and coats the back of a spoon.

Remove from heat, stir in the butter, and strain the mixture into a clean bowl. Let it cool for 5-10 minutes.

Pour the warm custard into the tart shell, smoothing the top with a spatula.

Bake at 180°C (350°F) for 35-40 minutes or until the top is golden and the custard is just set.

Allow the tart to cool to room temperature, then chill for at least four hours or overnight before slicing into smooth, rich pieces.