Narkel Posto Diye Ilish(Hilsa fish curry cooked in coconut-poppy seeds paste)

Sharing my Mom's recipe of Narkel Posto Diye Ilish(Hilsa fish curry cooked in coconut-poppy seeds paste):
Ingredients:
Hilsa/Ilish:4-5 piece
Freshly grated coconut paste:4 tbsp(please do not use coconut milk or powder)
Poppy seeds paste:2 tbsp
Green chili:4-5,slitted
Nigella seeds:1/2 tsp
Turmeric powder:1/2 tsp
Salt to taste
Mustard oil:5 tbsp
Hot water:1 cup

Method:

Clean and wash the hilsa pieces and smear with a dash of turmeric & salt.

Keep it for 5 minutes.

Make a paste of freshly grated coconut and poppy seeds.

Heat 3 tbsp of oil in a pan/wok.

Fry the hilsa pieces till they become golden.

Remove them from the pan.

Add another tbsp of oil to the remaining oil and heat it for few seconds.

Temper with nigella seeds and slitted green chilies.

Remove the chilies when they start changing the colour.

Add coconut-poppy seeds paste.

Cook it by stirring it continuously for 4-5 minutes.

Add a cup of hot water when the nice aroma of coconut-poppy seeds paste comes out.

Stir it well.

Add the hilsa pieces and chilies when the gravy starts boiling.

Cook for another 3-4 minutes.

Add a tbsp of oil,stir it again and remove it from the flame.

Serve it hot with steamed rice.