Apply salt to cleaned and deveined shrimp , and set aside for 15 minutes.
Wash the okra well, wipe it dry with a clean napkin, trim the edges cut into 1 to 1 & 1/2 inch pieces and set aside.
In your food processor/ mixer, add the grated coconut, red chillies, coriander seeds, garlic cloves, tamarind, and turmeric and make a smooth paste using a sufficient amount of water.
Heat oil in a thick bottomed pan, add onions and saute on medium heat until translucent.
Add the ground masala paste and saute until the masala starts bubbling and oozing out oil.
Rinse the grinder jar with water (about 1/2 cup), add this to the above mixture. Add another cup of water or adjust as per the desired consistency of the curry. Let everything come to a boil.
Add the cut okra pieces and cook for another 10 minutes on medium low heat or until okra is tender.
Add the marinated shrimps and cook until they are done, about 5 minutes. Check for seasoning, since we already added salt to the prawns, if required add more salt, a pinch of sugar to balance out everything.
Add coconut milk and let the gravy come to a boil. Done. Serve with steamed rice.