We’ve been eating this fish for at least ten years. It’s not difficult at all, but since I always make it with rice and these greens (http://amiralace.blogspot.com/2012/05/recipe-day-bangla-vegetables.html), it does require some fiddling in the kitchen. So I tried cooking the fish in the insert and the rice in a separate bowl. They turned out perfectly and it was easy to make the greens while the rest cooked, and to read a book for a while too.
About a pound of frozen fish (this is flexible)
One can coconut milk
1/2 tablespoon turmeric
Salt and cayenne to taste
Put the fish in the insert then mix everything else together and pour the sauce over. Put the trivet that came with the pot on top of the fish, then put a cup of well-washed basmati and a cup of water in the bowl. Cook for six minutes on high pressure, then let it naturally release for 10 minutes. The coconut milk frothed up quite a bit when I tried this and got into the rice, but that made the rice taste even better.
Since the fish is frozen and your coconut milk probably not hot, this one will take longer to come to pressure so the entire cooking time from when you turn on the pot to when you open the lid will be closer to thirty minutes.