There is an old Bengali saying that the power of endurance of a woman is like a Koi fish’s (Climbing Perch).
May manush’er praan, Koi maacher jaan!
Meaning both the Koi and a woman have great abilities to withstand pain. Try clubbing a live Koi for your meal and you will see how it takes you four or five, even more times to beat it to death! Koi is a pond fish, often found in slushy inlets, quietly hiding from a predator or fisherman. It has a dark appearance, the skin is rather thick. Koi fish is sweet, fleshy and has hook-like bones. I have once suffered the pain a Koi bone can cause to the throat, while eating a delicious curry made with mustard and green chilies, often called a Jhaal in Bangla. 
The Koi we eat should not be confused with the Japanese ornamental brocaded ones by the same name.
So today’s lunch was this Koi Maacher Jhaal, a simple mustardy curry spiked with fresh green chilies. 
Ingredients for Koi Maacher Jhaal are:
500 grams Koi fish, washed and cleaned
2 medium size ripe tomatoes, quartered
6-7 green chilies, slit lengthwise
Handful of fresh coriander, finely chopped
3 heaped teaspoons of freshly ground yellow mustard
Three-fourth teaspoons red chili powder
2 + 1 teaspoons turmeric powder
Half cup mustard oil
Salt
Heat mustard oil in a wok/thick pan until smoking. Rub two teaspoons turmeric and a spoonful of salt to the fish and shallow fry them, about two minutes on each side. Remove with a slotted spoon and keep.
In the remaining oil, add the tomatoes and green chilies and sauté for a minute or two. In a bowl, mix together the mustard, turmeric, and red chili powder. Add three cups of water and add the mixture to the tomato-green chili in the pan. Season with salt.
