In a large pan heat some coconut oil and add mustard seeds. When it starts to sizzle, add chopped onion and curry leaves. Stir and fry, on medium flame, till onion gets soft (3-4 minutes). Add ginger garlic paste and stir fry for 2 - 3 minutes.
Add tomatoes, green chilli and all the spices. Mix well and cook until tomatoes start to release its juices and get mushy.
Add water and bring to boil. Put the fish inside and let it simmer covered for about 10-25 minutes on low-medium flame. If the curry is too thick you can add some more water.
Now the fish is cooked and you can taste and adjust salt. One last step to do is to add one cup of coconut milk. Stir well and let it simmer for another 10 minutes.
Delicious Coconut Rawas Curry is ready to serve! Garnish with fresh coriander leaves and serve with bread or rice.
Recipe by My Indian Taste at http://myindiantaste.com/coconut-rawas-curry-recipe-rawas-indian-salmon-coconut-gravy/