Method:

• Wash, clean and cut mackerel into two. Then marinate it with  little salt,  1/2 tsp chilli pdr and a pinch of turmeric pdr.
• Wash and soak cocum in water.
• Grind pepper corns, chilli pdr, ginger and garlic to a paste. 
• Slice onion lengthwise. Cut green chillies lengthwise into two.
• Heat coconut oil and fry the fish pieces. Take out from oil when it is 3/4th done.
• Remove fish pieces from the oil. Saute onion pieces and green chillies in the balance oil. Then add the ground masala paste and saute again.
• Add one cup water to this, add salt, turmeric pdr and  cocum, boil it for 2 to 3 minutes. Add the  fried fish piececs and boil it for one more minute.
• Now add the coconut milk and cook it for 2 more minutes and finally add curry leaves. Remove from fire.
• Serve it with steamed rice!