400g/14oz ripe cherry tomatoes, halved
3 large mild red chillies, deseeded, finely chopped
5cm/2in piece fresh root ginger, grated
2 red onions, finely chopped
400g/14oz ripe plum tomatoes, quartered
300g/10½oz soft light brown sugar
2 tsp fish sauce (substitute soy sauce for vegetarians)
1 star anise
250ml/9fl oz white wine vinegar