In a large mixing bowl whisk together the eggs, egg yolks and sugar until smooth. Pour the mixture into a large heavy-based saucepan, gradually adding the milk, blending well. Heat the mixture slowly over low heat, stirring constantly until the mixture reaches 71-77c on a sugar thermometer or until the mixture coats the back of a wooden spoon.

Pour the custard through a fine sieve into a large bowl and stir in the vanilla, rum, bourbon and nutmeg. Cover the surface of the custard with cling film and chill, then refrigerate for at least 3 hours or overnight.

Just before serving, whip the cream to very soft peaks, beating in the icing sugar as you go. Gently fold the cream into the custard until evenly incorporated.

Pour the eggnog into glasses and decorate with the red currants and some grated nutmeg.