Bata Macher Jhaal / Bata Fish in Mustard Sauce

INGREDIENTS:
Bata Mach / Bata Fish (4-6).
Mustard paste (4 TBs).
Mustard oil (4 TBs).
Turmeric powder.
Salt to taste. 
Finely chopped onions (1-2).
Curd (1-2 TBs).
Green chilies (4-8).
kalonji (1/2 Tsp).

PROCEDURE:
Mix pinch of salt and turmeric powder over neatly cleaned fishes and kept aside.
In the meanwhile heat oil in a pan and as smoke emits add fishes slowly one by one and fry them well on both sides.
Now remove them from oil and keep aside.
Add kalonji to oil and as they pop up, add chopped onions and saute well, now add a tsp of curd and saute well, add mustard paste, green chilies slit, salt and turmeric powder and saute well.
Now add water required for gravy and allow it to boil, as it starts boiling add fried fishes and allow it to boil for few minutes, now off the flame.
By now the taste and aroma of green chilies are in the thick mustard gravy.
Now serve it with hot steaming bowl of rice and enjoy its great taste.