You don’t need an ice-cream machine for this frozen dessert. The plums are stewed and then blended as sauce. I don’t normally like to change a fruit’s texture in a liquidiser, but stewed plums have a defeated look which is no loss.
Make a sabayon with the egg yolks, sugar and honey. This entails whisking the ingredients together over a very low heat until the mixture cooks, first fluffing up and then thickening, without scrambling the egg.
Bring the milk and vanilla pod to the boil, then strain. Whisk the hot flavoured milk into the sabayon, then leave to cool.