A preserve to spice up any dish is an easy recipe to cook up - just keep your fingers away from your eyes!
Many chilli jam recipes call for peppers, or ginger, or garlic, or tomatoes, or ... well, you name it. But all you really need is sugar, chillies (obviously), vinegar and a source of pectin, which makes jam set. Learn to combine these four, then you can start adding bells and whistles. But this recipe, adapted from the blog A Life of Geekery is good enough to stand on its own.
Start by sterilising three or four small jars and their lids in the oven for 15 minutes at 140C/275F/gas mark 1. It's fine to reuse them, so long as the seals are intact. While these are heating, place a saucer in the fridge (we'll explain why later), trim and deseed 150-200g of small red chillies, and either chop them up them finely or give them a quick whizz in a blender. (This will also save you from ending up with stinging hands - or worse.)
Place the chillies in a large saucepan together with 400ml cider vinegar and either 1kg jam sugar (which includes pectin) or 1kg of normal sugar and two or three large cooking apples, which you have pierced in several places. Bring everything to a simmer, then cook at a rolling boil for about 15 minutes, stirring occasionally with a wooden spoon.
Turn off the heat, take the saucer out of the fridge and drop a little jam on it. Put it back in the fridge, wait a couple of minutes and see whether it's begun to set, in which case you can start filling your jars. If not, put the jam to boil again and check for set after another four or five minutes. Whatever happens, after three or four tests, turn off the heat. Better jam that's a little runny than chilli-flavoured toffee.
Remove the apples (if used) and ladle the jam into your still-hot jars, with the help of a funnel if necessary. Don't worry if the apples have broken up a little, just try to fish out the largest chunks. If it seems that all the chilli flakes are rising to the top of the jars, immediately turn them upside down for 15-20 minutes to redistribute the contents - but don't forget to turn them the right way up again.
Phil Daoust is a food writer based in England and France. Twitter:@philxdaoust
Photo: Sweet chilli jam adds a neat heat to any snack as a relish or dip. Photograph: Colin Campbell for the Guardian