Classic British Custard Tart

In a mixing bowl, combine the plain flour, icing sugar, and cold diced unsalted butter. Rub the butter into the dry ingredients using your fingertips until the mixture resembles fine breadcrumbs.

Add the single egg yolk and cold water to the bowl. Mix gently until the dough just begins to come together into a shaggy mass.

Form the dough into a flat disc, wrap tightly tightly, and refrigerate for 1 hour to allow the gluten to relax and the butter to firm up.

On a lightly floured surface, roll out the chilled pastry disc using a rolling pin until it is about 3mm thick.

Carefully transfer the rolled pastry into the 20cm tart tin, pressing it gently into the corners. Trim the overhang, prick the base with a fork, and refrigerate for 30 minutes.

Preheat your oven to 190C/375F. Line the chilled pastry shell with parchment paper and fill to the brim with baking beans. Blind bake for 15 minutes to set the edges.

Remove the parchment paper and baking beans. Return the tart shell to the oven at 190C/375F for a further 5 minutes until the base is dry and light golden. Remove from oven and reduce the oven temperature to 140C/285F.

While the oven temperature drops, combine the whole milk, double cream, and vanilla bean paste in a medium saucepan. Gently heat over medium power until it begins to steam and bubble slightly at the edges, about 85C/185F.

In a separate heatproof mixing bowl, whisk the 5 egg yolks and caster sugar together until just combined and smooth.

Slowly pour the hot milk mixture over the egg yolks while whisking constantly to temper the eggs and prevent them from scrambling.

Pass the custard mixture through a fine sieve into a jug to remove any accidental egg clumps and ensure a perfectly silky texture.

Place the blind-baked tart shell on the middle shelf of the 140C/285F oven. Carefully pour the warm custard directly into the shell until it reaches the brim. Generously grate whole nutmeg evenly over the surface using a fine grater.

Bake the tart at 140C/285F for 30 to 35 minutes. Check the tart by gently nudging the tin; the edges should be set but the center third should still have a distinct, gentle wobble.

Remove the tart carefully from the oven and leave it to cool completely in the tin at room temperature for at least 1.5 hours. The residual heat will finish setting the custard perfectly.