Frozen Plum, Cinnamon and Port Parfait

This is more of a frozen mousse than an ice cream. The cinnamon and port, whilst scarcely detectable in themselves, combine with the plums to make a really exquisite flavour. Don’t make it with Victoria plums, which are so good to eat. They are a dessert fruit and when cooked seem to lose their attraction and become bland tasting. Any of the other yellow or dark red, rather sharp-tasting plums are ideal.