This fish curry is traditionally made in an earthen pot which lends a unique flavour to the dish. If you do not have one, a regular kadai or pan can be used.
Clean the fish and cut into small pieces and keep aside.
Heat oil, crackle mustard seeds and then add fenugreek seeds and curry leaves. Next add chopped shallots, ginger and garlic and sauté till the onions turn light golden brown.
Make a paste with red chilli powder, kashmiri chilli powder and turmeric powder and add to the above and sauté again till the oil clears.
Add 1 cup water and then put in the kokum pieces and salt and bring to boil.
Add the fish pieces and cook till done. Stir in between and add more water if necessary. The gravy for this dish is meant to be a thick one just coating the fish pieces.
Garnish with curry leaves.