Well ahead, make the Almond Parfait: put the milk and vanilla pod in a pan and bring to just below the boil. Whisk the egg yolks and sugar together in a heatproof bowl until light. Pour the milk over the egg mixture, then return to the pan and cook, stirring continuously, until the custard coats the back of a spoon. Remove from the heat. Pass through a fine sieve, stir i