Vanilla blackcurrant ripple

For the vanilla ice-cream:
milk 600ml
vanilla pod 1
egg yolks 6
caster sugar 150g

For the blackcurrant ripple:
blackcurrants 250g
caster sugar 3 tbsp
water 100ml

To make the ice-cream first pour the milk into a saucepan. Slice the vanilla pod in half lengthways and scrape the sticky black vanilla seeds into the pan with the point of a knife. Drop the scraped pod in, too, then bring the mixture almost to the boil. Turn off the heat just before it boils. Leave for 30 minutes or so, for the vanilla to flavour the milk.

Beat the egg yolks and caster sugar until light and fluffy. Discard the vanilla pod, then pour the milk through a sieve into the yolks and sugar, stirring to a thin custard, then pour into a clean saucepan.

Put the custard over a moderate heat and, stirring almost continuously with a wooden spoon, bring it slowly towards the boil. Once the custard is thick enough to thinly coat the back of the wooden spoon, remove from the heat, pour into a cold basin and leave it to cool. Refrigerate the custard for a good half hour before pouring into an ice-cream machine and churning until almost frozen.

Transfer the ice-cream into a freezer box and freeze for two hours.

Remove the blackcurrants from their stems. Put the fruit in a small saucepan with the sugar and 100ml of water and bring to the boil. Lower the heat and simmer for 5 or 6 minutes until the currants are starting to burst and the liquid has become a deep purple colour. Turn up the heat and boil rapidly for 2 or 3 minutes until the liquid has formed a thickish syrup, then remove from the heat and leave to cool.

As the ice-cream is starting to firm in its freezer box, spoon in the blackcurrants and swirl through the ice-cream to form ribbons of purple. Avoid the temptation to over-mix. The ice-cream should be mostly creamy white with ripples of blackcurrant through it. Return to the freezer until set.