Wash, halve and de-stone the plums. Peel, quarter and core the apples. Peel and roughly chop the onions. Peel and crush the garlic. Put all the fruit and vegetables in a preserving pan with the sultanas, vinegar and spices. Bring to a boil, stirring frequently, then simmer for 30 - 40 minutes until the ingredients are very soft. Add the sugar. Stir over gentle heat until completely dissolved and then simmer uncovered until thick and jam-like. Spoon into clean warm jars. Cover.
