Bhappa Shorshe Ilish (Mustard Hilsa fish)

Being a Bengali I can't but love this dish. Authentic to East of India I am sure friends from Orissa, Assam & Bengal will drool at the sound of this dish.

Raw hilsa reference.

Ingredients:

1 Ilish (Hilsha) fish, cut into steaks
2 tablespoon mustard (or ground mustard paste)
3 tablespoon white til paste
6 green chilies
1 teaspoon turmeric powder
2 tablespoons oil, mustard oil preferred
Salt to taste (approximately 1 tbsp salt)
Few sprigs of coriander leaves for garnish

Method:

Wash the fish well.
In a container mix the mustard paste, til paste, turmeric, 1tbsp of mustard oil and salt.

Bhappa ilish

Rub this paste on the fish steaks and put the fish in a steamer. Add the green chillies slit mid way on the fish. Add a dash of mustard oil (about  a tsp each) on the fish.
I'd use a set of pressure cooker partitions and set them one on top of the other with a lid on the top-most container.
Add about 1/4th cup water in the cooker and let the fish steam over medium heat till about the release of the first pressure.
Switch off. Let the pressure settle. 
Carefully transfer the fish into a serving dish. You could garnish this with a few sprigs of coriander spread over the dish.

Serve with hot steamed rice.