Prepare the oven and ramekins

Preheat the oven to 180°C / 160°C fan / gas 4. Place 4 small ramekins in a deep roasting tin. The tin needs to be deep enough to hold water around the ramekins while they bake.

Infuse the cream

Pour the double cream and milk into a saucepan. Split the vanilla pod lengthways, scrape out the seeds and add both the seeds and pod to the cream mixture.

Warm gently over a medium heat until the cream is just below boiling point. Remove from the heat as soon as small bubbles appear around the edge.

Whisk the yolks

Put the egg yolks and caster sugar into a mixing bowl. Whisk for about 1 minute, until the mixture turns paler and slightly thickened.

Make the custard

Slowly pour the hot cream into the egg yolk mixture, whisking continuously as you pour. Strain the mixture through a fine sieve into a jug, then skim off any pale foam from the surface.

Bake gently

Pour the custard into the ramekins, filling them almost to the top. Add hot water to the roasting tin so it comes part-way up the sides of the ramekins.

Place in the oven and bake for 30–35 minutes, or until the custards are just set with a soft wobble in the centre. They should not be completely firm.

Chill

Carefully lift the ramekins from the water bath and leave to cool briefly. Transfer to the fridge and chill completely, ideally for several hours or overnight.

Caramelise the tops

When ready to serve, sprinkle a thin, even layer of caster sugar over each chilled custard. Use a blowtorch to caramelise the sugar until golden and crisp.

Leave for a minute or two until the sugar hardens, then serve.