1 vanilla pod (split in half or 1 teaspoon vanilla essence)
450 ml cream
3 egg yolks
50 g caster sugar
75 ml water
3 egg whites (stiffly beaten)
Put the split vanilla pod in a small saucepan with the cream.
Place the pan over low heat and scald the cream (bring it to just under boiling point).
Remove the pan from the heat, cover and leave the cream to infuse for 20 minutes.
Strain the into a small mixing bowl and let it cool.
If you're using the vanilla essence, add it at this stage.
In a medium-sized mixing bowl, beat the egg yolks until they're well blended.
In a small saucepan, dissolve the sugar in the water over low heat, stirring constantly.
When the sugar has dissolved completely, increase the heat a bit and bring the syrup to boiling point, and boil rapidly until a little of it, spooned out of the pan and cooled, will form a short thread when drawn out between your index finger and thumb.
Remove the pan from the heat and let the syrup stand for 1 minute.
Pour the syrup over the egg yolks in a steady stream, stirring constantly until the mixture is thick, fluffy and mousse-like.
Mix in the cooled cream and, with a metal spoon, fold in the egg whites.
Pour the mixture into the ice cream container and freeze.