Heat the oven to 200C/fan 180C/gas 6. Roll the pastry out on a lightly floured worksurface, then use it to line a 28cm loosebottomed tart case. Trim the edges, line the tart with baking paper, then tip in some baking beads and bake for 15 minutes. Remove the beads and paper, pierce the pastry with a fork and turn down the oven to 180C/fan 160C/gas 4. Bake for 10 minutes more, then turn down the oven again to 120C/fan 100C/gas 1. Whisk the egg yolk, brush it over the base, and bake the case for another 5 minutes.