Clean up the sardines, slice them as per preference and marinate them with the ingredients given under "for marination" for 30 minutes to 1 hour
Soak the tamarind in 1½ cups of water.
In a mud pot (preferably), take the squeezed tamarind water and all the other ingredients cited under "rest of the ingredients". Bring this to a boil on stove top.
Once it comes to a nice boil add the marinated fish and let it cook for 5-7 minutes.
In the meantime, grind the coconut to a smooth paste and add it to the curry when it starts boiling again.
Cook for a few more minutes till the raw smell of the coconut disappears and the curry thickens.
Temper with the ingredients given under " for tempering" and pour it over the curry. Serve it with plain white rice.