Old-school tomato chutney - Eat Well Recipe

1 kgTomatoes, ripe, cored and chopped (Main)1Apple, peeled and chopped1Onion, chopped½ cupRaisins, I use the jumbo raisins2 TbspMalt vinegar1 ¼ cupsSoft brown sugar1 ½ tspMild curry powder1 ½ tspMustard powder1 TbspFlaky sea salt1 ½ tspCornflour, for thickening