For paste : 1 tsp cumin seeds, 1 chopped tomato, 1" ginger, 1 chopped onion, 1/2 tsp black pepper powder, red chilli powder as needed, 1/2 tsp haldi powder. Grind it and make a fine paste. Once it is done then keep aside. Now take 6 pieces rahu fish. Wash it well with haldi powder and salt twice or thrice. Drain the water. Then marinate the fish with haldi powder and salt. Once it is done then keep aside..

Now heat oil in a iron kadai. Fry for few seconds 1" cinnamon stick and 1/2 tsp black cumin seeds / kalonji, Then add the masala paste. Fry till the raw smell of masala goes off....

Then add the fried fish. Stir it gently other wise the fish will break.. Then add 1/2 cup water. Cover and boiled it for few minutes.

Now I am going to add mustard paste/ Kasundi. Mix it wll and don't over cook. Other wise the curry will be bitter. Once it done. Then transfer to a serving plate.