Clean the fish & cut into small pieces. Marinate fish with turmeric powder & salt.Half fry it in mustard oil. Boil 6-7 cup of water. Add potato, saroo, desi aloo, buta dal, salt, haldi & leave it until half cooked. Then take 4-5 tsp mustard oil in a kadai. Fry dried chilli, teja patra & pancha phutan until it crackles. Add all of the paste, salt, turmeric powder, chilli powder & fry it till oil comes out from paste. Then add boiled veges with fish & mix each other propely. Let it cook till becomes gravy. Sprinkle dalchin powder, roasted cumin powder. Now the Ilish Machha Mahura is ready.