Photograph: Jonathan Gregson
Put all the ingredients in a pan and place over a moderate heat. Stir until the sugar dissolves, then simmer for 30 minutes until most of the liquid has evaporated.
Cool, then remove the cinnamon and cardamom pods. The star anise look pretty – but don't eat them!
Get ahead: make up to 3 days ahead; chill.
Kitchen secret: if you want extra for leftovers, you can easily double the recipe.