Preheat the slow cooker if necessary; see the manufacturer's instructions. Put all the ingredients in the slow cooker pot and mix together. Cover with the lid and cook on high for 6–8 hours or until thick and pulpy, stirring once or twice.
Warm 5 clean jars in the bottom of a low oven. Spoon in the chutney, place a waxed disc on top and leave to cool. Seal each jar with a screw-topped lid, then label. Store in a cool place for up to 2 months. Once opened, store in the refrigerator.