Clean and wash the fish slices and rub turmeric all over them. Cover and keep aside.
Grind all the ingredients under paste till smooth with a tablespoon or two of water.
Heat coconut oil in a large pan or kadhai and add mustard seeds. Once the seeds start spluttering, add the ground paste and cook while stirring once in awhile for 10 minutes.
Slide the fish into the pan, and add salt and 3/4 cup water. Mix gently so as not to break the fish.
Bring the curry to a boil, and lower the heat to a simmer. Add curry leaves and simmer for 15 minutes.
Top with coriander leaves and serve this spicy kingfish curry with steamed rice.
