1. Heat the oil and gently cook the onions for 10 minutes until transparent but not coloured.
2. Add the cherries (including the syrup), balsamic vinegar, sultanas and star anise.
3. Bring to the boil then simmer for 45 minutes until reduced and thickened.
4. Serve warm as an accompaniment to pork or duck.
You can also allow this to cool and serve with cheese, pâté or cooked meats.