Coat pomfret in salt and turmeric and set aside. Grind mustard seeds and keep in warm water. Keep grated coconut handy (if it's frozen, keep in a little warm water). Meanwhile pan-fry the pomfret in shallow mustard oil until golden and cooked.
In a pan, sauté mustard seeds and green chilli. Add a little turmeric, chopped tomatoes and the ground mustard seeds with the water; then add salt to taste. Put in the coconut and let the curry thicken a little bit before sprinkling sugar. Finally add fish. Simmer on low covered for a few minutes and serve with coriander garnish. Dash of lime on top with rice seals the deal! Yum.
