Of course, if you are feeling virtuous or want to share with the kids you can leave the vodka out.... or you could just feed them some vanilla!
You will need.....
250 ml double cream
150ml full fat milk
Grated rind and juice of 1 lemon and 1 lime
100ml Greek yogurt
150g sugar - more or less according to taste
Slug of vodka
Measure out 100ml of cream and put into a milk pan with the milk.
Whisk the eggs, sugar, rind and juices together.
When the milk and cream are just coming to the boil, pour over the egg mix and whisk well.
Return to the pan.
Cook gently, stirring continuously until the custard coats the back of the spoon.
Transfer to a bowl and cool quickly - I stood mine in a bowl of iced water.
When cold, add the vodka.
In a separate bowl, whisk the remaining cream until it just holds its shape and then stir in they yogurt.
Pour the lemon custard in and mix gently.
Pour into a plastic container and place in the freezer.