Very seasonal, but very much a store cupboard ingredient. Out of season, ordinary caperberries can be used.
Day 1: Layer the berries in a tub with the salt and sugar. Pour the water over and leave for 24 hours.
Day 2: Bring the vinegar to the boil with the sugar and spices. Rinse the berries and cover with the vinegar. Ideally leave for a few weeks or months before using them.</