Grind together the grated coconut, coriander seeds, black peppercorns, chopped onion, tamarind paste, red chilli powder and salt into a smooth masala.Heat oil in a non-stick pan.
Add onion, salt and turmeric powder. Mix well and cook on medium heat until onion turns light brown.
Add prawns, ground masala and sufficient water to get a curry consistency.
Stir to mix and cook for two minutes.Dissolve the atta in a little water and add to the prawns.
Mix well, adjust the salt and add red chilli powder.
Mix again and cook for another two minutes. Serve hot with steamed rice or phulkas.