Trivandrum-style mackerel curry

Fresh mackerel fish cooked in spicy and flavoursome gravy made with coconut paste, drumsticks, and tomato tastes incredible. This fish curry is well-balanced with the perfect amount of spiciness and sourness. Check out the recipe for Trivandrum-style fish curry.

Ingredients
3 mackerels
¾ cup grated coconut
3-4 shallots
½ drumsticks (cut into slices)
2 ripe tomatoes
3-4 green chillies (split)
¼ tsp turmeric powder
2½ tsp chilli powder
2 tsp coriander powder
¼ tsp fenugreek powder
Gooseberry sized ball of tamarind
4 sprigs curry leaves
1 tbsp coconut oil
Salt as required

Preparation
Clean the fish and cut them into fillets
Soak the tamarind in water
Dry roast the chilli powder and coriander powder on low flame until the raw smell of the powders are gone
Grind the grated coconut with shallots, turmeric powder, dry roasted chili and coriander powders, and salt and tamarind water
Pour enough water and mix into gravy
Take the fish fillets in an earthen chatty
Add the previously mixed gravy, some water, tamarind pieces and salt
Boil with the lid on
When the gravy begins to bubble up add the fenugreek powder, drumsticks, green chillies, tomatoes, some curry leaves and salt
Cook on low flame with the lid on
Rotate the chatty gently to mix everything when the gravy boils rapidly
Do not mix or stir the curry using steel or wooden spoons as the fish pieces may crumble
Oil begins to appear on the surface when the gravy becomes thicker
Turn off the flame 
Sprinkle some curry leaves and fresh coconut oil as well
Close the lid and keep the curry aside for some time
Fish curries shouldn't be eaten as soon as they are cooked
Enough time must be given for the fish fillets to absorb the flavours in the gravy
The mackerel curry could be served at least half an hour after it is cooked.