It is mainly the food of Bagerhat region. It is a very rich but fun food. In the Khulna region, the big shoal is called gajal fish.
So it can also be called spider biren (biryani).
(Recipe Credit: Shamima Sultana)

Ingredients

Shoal fish: one and a half – weighing two kilograms
Onion chop: 2 cups
Onion paste: 1 cup
Garlic paste: 2 tbsp
Ginger paste: 2 teaspoons
Salt: Quantitatively
Turmeric: 2 teaspoons
Chili powder: 3 teaspoons
Cumin powder: 3 teaspoons
Coriander powder: 2 teaspoons
Bay leaves: 2 p.m.
Oil: 1/2 cup
Raw chillies (whole): 8-10
Coconut milk: 4 cups
Sugar: 2 teaspoons
Steps

Step 1
First I will cut the shoal fish, wash and clean it and cut it into small pieces.

Step 2
Fry the fish in oil with salt and turmeric over medium heat (it will not be hard fried).

Step 3
I will remove the fish from the oil. Now I will fry the onion in that oil and take it out.

Step 4
This time I will give onion paste, garlic paste, ginger paste in oil.

Step 5
I will fry the spices, when fried I will give a little water.

Step 6
I will spice the rest of the powder. I will fry the spices again, when fried I will give coconut milk.

Step 7
When the coconut milk boils, I will give pieces of fried fish and bay leaves. I will cook over medium heat.

Step 8
When the vegetable oil is boiled, I will add raw chilli and sugar.

Step 9
After 2/3 minutes I will give half barista. Cover and cook again for 2/3 minutes.

Step 10
This time, before unloading, I will shake the rest of the barista and take it down