(10 large ripe roma tomatoes, coarsely chopped), onion (2 red onions, coarsely chopped), sugar (1 cup (220g) raw sugar or demerara sugar), vinegar (1/2 cup (125ml) cider vinegar), salt (3 tsp sea salt flakes), ginger (1 tbsp finely grated ginger) and chilli (1 tsp dried chilli flakes (optional)), if using, in a large ...