Place the canned tomatoes, chilli, garlic, ginger and fish sauce into a food processor and blend until smooth.
Place the tomato sauce into a non-reactive pan over a medium heat and add the vinegar, sugar, cardamom pods and raisins. Bring to the boil then add the chopped fresh tomatoes. Reduce the heat and simmer for 45-55 minutes, or until the sauce has thickened to a chutney or jam-like consistency.
Transfer to sterilised jars and seal until ready to use. The jam should keep for 2-3 weeks in the fridge.