Hilsa fish - 500 gm
Mustard oil - 6 tbsp
Mustard seeds (Black) - 3 tbsp
Mangaraila (kalonji) - 1 tsp
Green chilli - 4-5 (slit)
Curd - 1 tbsp
Salt - 2 tsp or as desired
Turmeric powder - 3/4 tsp
Water - 2 cup (approx.)
Coriander leaves (chopped) - 2 tbsp
Method of Preparation
1. Soak mustard seeds, for 15 minutes, in 1/2 cup of water and 1/4 tsp salt.
2. Add curd and 2 green chillies, and grind into a fine paste. Add more water if required while grinding. Keep the paste aside.
3. Cut and clean Hilsa fish and wash. Add 1 tsp salt and 1/2 tsp turmeric powder, mix and set aside.
4. Heat 1 tbsp oil in a nonstick pan and fry the fish pieces lightly on both sides.
5. Add 2 tbsp oil and heat. Add kalonji and rest of the green chillies, and fry for 1/2 a minute.
6. Add 1 and 1/2 cup water, salt (as per taste), 1/4 tsp turmeric powder and mustard paste.
7. Bring it to boil, stirring continuously. Add the fish pieces, keep boiling for another minute.
8. Lower the heat and simmer for 15 to 20 minutes, till the gravy thickens to desired consistency.
9. Add corinader leaves and mix lightly.
10. Pour the rest of the mustard oil over the fish gravy, mix and simmer for another minute.
11. Remove from heat and serve with plain rice.
Notes & Tips
1. Grinding mustard seeds is the most critical step in this preparation. Salt and curd are added to the mustard to avoid the bitter taste. Also, the grinding should not be overdone as that too will make the mustard paste bitter. Ideally, mustard should be ground on a "sil-lodha", if you have one, and it should be ground to the desired fineness in one shot.
2. This is a typical Bengali preparation of Hilsa fish, called "Ilish Sorshe Bata (Jhal)". This is how my mother-in-law makes it. Traditionally, however, this fish is not fried and is thrown raw into the gravy. It is then simmered for a very long time till the fish is done and gravy thickens.