This is sometimes called acar kuning, yellow acar; the colour comes from turmeric. Acar is normally eaten cold, but this version can be served hot as a side-dish with hot vegetables. For serving cold, on the other hand, it can be made several days in advance, and kept in the fridge in a covered container. It is also suitable for freezing. Thaw it out completely before serving it cold, or reheating it gently in a saucepan for 3–4 minutes.