If you don’t want it very hot, then skip to step 2. Place everything except the last two ingredients in to a blender and blitz. You may want to wear gloves as chilli in your eye is not great.
Transfer everything in to a saucepan and simmer for 10 minutes.
In a jug, mix together the water and cornflour and stir and simmer for a final 5 minutes and bottle in to a sterilised jar.