Blend the chillies, peppers, garlic, shallot and tomatoes in a food processor until smooth.
Pour the purée into a stainless steel saucepan, add the sugar and vinegar, then bring to the boil, stirring from time to time. Reduce the heat and simmer for 40-60 mins until thick, stirring regularly, especially in the latter stages of cooking.
Pour into large, warm sterilized jars then cool. This will keep for up to 2 weeks in the fridge.