Strawberry & vanilla ice cream

Method:1. Purée the strawberries until smooth then sieve. Whisk the caster sugar and egg yolks together until pale and thick. Bring the cream to the boil, then whisk into the egg yolk mixture. Pour back into the pan and cook over a low heat for 4-5 minutes until the custard coats the back of a wooden spoon - don't boil it or the eggs will scramble. Strain into a bowl and cool. Add the strawberry purée and a little lemon juice to taste. Chill.2. To make the vanilla ice cream, bring the milk, cream and vanilla pod to the boil. Remove from the heat and set aside for 15 minutes to infuse. Whisk the egg yolks and sugar together in a large bowl until pale and thick. Whisk in the milk mixture and follow the method for the strawberry ice cream.3. Pour the ice cream mixtures into separate plastic freezer boxes and freeze for about 4 hours, whisking every hour until half frozen. Dollop alternate spoonfuls of strawberry and vanilla ice cream into a large freezer box, tap sharply on a work surface to level and swirl together using a knife. Cover and freeze until solid.