Tip the capsicum,chillies,ginger and garlic into a food processor,then whiz until very finely chopped.

Scrape into a heavy-based pan with the tomato paste,sugar,salt,vinegar,bay leaf and coriander seeds,then bring everything to the boil. Skim off any scum that comes to the surface,turn the heat down low and allow to simmer for about 50 minutes,stirring occasionally.

When the jam becomes sticky,continue cooking for 5 minutes,stirring frequently so that it doesn't catch and burn. It should now look like thick,bubbling lava.

Cool slightly,transfer to sterilised jars,then leave to cool completely. Keeps for 3 months in a cool,dark cupboard — refrigerate once opened.