Vanilla pastry cream

Split the vanilla bean and scrape out some of the seeds.

Put the milk in a medium saucepan with the vanilla pod and seeds.

Bring to a simmer over medium heat, 4 to 8 minutes.

Sprinkle the sugar over the egg yolks and whisk until smooth and lighter in colour.

Set the simmered milk aside to cool about 15 minutes so the vanilla infuses and it is not too hot for the yolks.

Sift and whisk the cornstarch into the yolk mixture until no lumps remain.

Remove the vanilla pod from the milk.

Drizzle half a cup of the hot milk into the yolks while whisking vigorously to temper them, then whisk in the rest of the milk.

Pour back into the pot through a fine mesh sieve to catch pod pieces.

Whisk gently and continuously over medium heat with a narrow French whisk, centre to edge and back, 5 to 8 minutes until thickened and bubbling.

Stir in the cold butter until melted and silky.

Transfer to a bowl, press parchment paper onto the surface to stop a skin, and chill at least 2 hours, up to 24.

Loosen the chilled cream with an electric hand mixer on low, about 30 seconds, until supple but still thick.

Variation: for creme diplomate, fold in one cup of heavy cream whipped to stiff peaks; for a version that will sit, first stir in one teaspoon of gelatin melted with three tablespoons of water in the microwave for 30 seconds.

Pipe little dollops, as between puff pastry layers for a mille-feuille.