Puree the coconut until smooth along with all the other ingredients up to and including the water.
Heat the oil in a large, non-stick frying pan. Add the yellow peas and mustard seeds, toast until the mustard seeds burst. Add the curry paste, cook for approx. 5 mins. Add the curry, turmeric, chilli powder and tomato puree, cook briefly. Pour in the coconut milk and water, add the jackfruit, bring to the boil, reduce the heat. Simmer the curry for approx. 20 mins. Stir in the sugar. Garnish the curry with coriander.