Wash the fish thoroughly and keep aside. Make sure to change water and wash couple of times. (Good to use rock salt or just normal salt to brush over the pieces while cleaning.) Any fish will do as long as it is fresh.

In a wok, heat coconut oil, splutter the mustard seeds and curry leaves. Once the seeds crackle, add the chopped ginger, garlic and shallots. Saute well for 2-3 minutes until raw smell goes.

Add the spice powders-red chilli powder (kashmiri is used in the pic, hence the awesome red color), turmeric powder, fenugreek powder along with salt and saute again for 3-4 minutes on low flame.

Now- add the fish pieces and the kudampuli pieces. Add some more salt if required, pour in enough water to cover it all and let it cook on medium flame until the fish is cooked well, it should take about 10-15 minutes. (Kerala fish curry is best cooked in clay pots, so move them there right now, if you got one. But it is better to do the initial steps before adding fish in a normal wok so that you can the frying done fast)

Time to taste, open and check and adjust salt if required.