For the pastry, put the flour and butter in a food processor and blitz until it resembles breadcrumbs.

Add the icing sugar and pulse to combine.

Add the egg yolks and 10–20g cold water, then pulse until the dough just comes together.

Turn out onto a lightly floured surface, shape into a disc, wrap in cling film and chill for at least 30 minutes.

Preheat the oven to 180°C/160°C fan/gas mark 4.

Roll out the pastry and line the tin. Prick the base with a fork, then line with baking parchment and fill with baking beans.

Blind bake for 15 minutes, then remove the parchment and beans and bake for another 5–10 minutes until lightly golden.

Meanwhile, for the rhubarb jam, put the rhubarb, 150g caster sugar, lemon juice and zest in a saucepan.

Cook over a medium heat for 10–15 minutes, stirring occasionally, until the rhubarb is tender and the jam has thickened.

Leave to cool slightly, then spoon into the blind-baked pastry case.

For the custard, heat the milk and cream in a saucepan until just simmering.

In a separate bowl, whisk the egg yolks, 70g caster sugar and cornflour until pale and thick.

Gradually pour the hot milk and cream onto the egg yolk mixture, whisking constantly.

Pour the mixture back into the saucepan and cook over a low heat, stirring constantly, until the custard has thickened.

Stir in the vanilla bean paste or extract and salt.

Pour the custard over the rhubarb jam.

Bake for 25–30 minutes, or until the custard is set with a slight wobble.

Leave to cool completely before chilling in the fridge for at least 2 hours.