Put the garlic, chillies and sliced ginger into a food processor and blend to a paste. Add the tomatoes and whizz once more using the pulse button to coarsely chop the tomatoes.

Tip the mixture into the 18cm Saucepan and add the sugar, vinegar, star anise and fish sauce. Bring to the boil, reduce to a simmer and leave to cook, stirring now and then and then more frequently towards the end, for 50 minutes - 1 hour or until the mixture is well reduced and jammy. Remove and discard the star anise and leave the jam to cool. It will thicken even more as it cools.

Pour the jam into sterilised jars and seal with airtight lids. This will keep well in the fridge.