Somewhere between a spread and a savory jam, this paste is lovely on bread or served as a condiment with a meaty game stew. It’s also wonderful made with blackberries picked from the hedgerows in autumn.
Heat the blackcurrant purée in a saucepan with the sugar and vinegar, stirring until the sugar has dissolved.
Cook very gently until it has reached the setting stage – when a little left to cool on a cold plate rapidly forms a skin on top (or use a jam thermometer; the mixture is ready when it reaches 140˚C).
Remove from the heat and stir in the cacao until it has melted.
Pour into a warm, sterilized jam jar, allow to cool slightly, then seal. This paste should keep well for at least 3 months if stored in the fridge.