Stone the dates and chop the flesh finely. Grind the garlic, ginger and mustard seeds together and crush the cardamoms and cloves. Place the sugar in a pan, pour on the vinegar and heat gently. When the sugar has dissolved, add the dates, chilli powder, garlic, mustard, ginger, cardamoms, cloves and cinnamon stick and cook over a low heat until the liquid thickens but the dates are not pulpy. Add the sultanas and cook for a further 2 minutes, then discard the cinnamon stick, add salt and set aside to cool. From "A taste of Sri Lanka" by Indra Jayasekera, Isbn #962 224 010 0