1 1/4 cup (300 ml) 1/2 pint double cream (heavy cream)
1 1/4 cup (1/2 pint) 300 ml milk
2 vanilla pods, split
3/8 cup (85 g) 3 oz granulated or loaf sugar
scant 1/2 (us) cup (100 ml) hot water
4 egg yolks
1. Put the cream and milk into a large saucepan. Scrape the seeds from the vanilla pods and add those and the pods to the cream. Heat over a low flame until the cream and milk come to scalding point. Remove from the heat and leave to infuse for a minimum of 30 minutes.
2. Put the sugar and water into a small saucepan. Set over a low heat until the sugar is completely dissolved. Bring to the boil and simmer until the syrup forms a thread when pulled between your finger and thumb. Remove from the heat and cool for 1 minute.
3. Whisk the egg yolks in a small bowl. Pour the hot syrup onto the yolks in a thin stream, whisking all the time. Continue to whisk until the mixture is thick and mousse- like in consistency.
4. Remove the vanilla pods from the cream, but do not strain and remove the little seeds. Stir the cream into the mousse base.
5. Freeze the mixture in an ice cream churn, alternatively put the mixture into a shallow tray and leave in your freezer for 1 hour. Break up the mixture with a fork and continue to freeze for a further hour. Break up the mixture once more and then freeze until firm.
6. Leave the mixture to 'mature' in the freezer for at least 2 hours before serving. Remove from the freezer and place in the refrigerator for 15 minutes before serving.