Marinate the Shol fish with 1/2 Tsp salt and 1/2 Tsp turmeric. Nicely blend the spice with your hands and leave it for 10 mins.
Now I will proceed toward the earthen fireplace, I will fire it up, heat the wok (karai) and add the oil for frying the fish.
Add the Shol fish pieces when the oil is hot. Fry the fish from both sides. Fry it till it is brown in colour and the skin will try to shrink. (Pro tip: Do not flip the pieces too early because shol skin sticks and tears if the crust does not set.)
Add some oil and then add the bay leaf, Jeera and the dried red chili. Sauté these ingredients.
Then add the finely chopped onion till it is golden brown and add the potatoes, fry the potato in the same way.
Add salt as per taste, and then add the ginger and garlic paste when the potatoes are half cooked.
Cook it for 5 mins. Add the spices powder such as coriander, red chili, and turmeric. Add little water so that the spices do not burn.
Cook it for 5 mins. Add the tomatoes and then a little water again so that it does not get burned and cover it with a lid. Leave it for 5 mins.
After 5 mins you will see that the oil and spices are separated, now add some water again to make it a gravy (preferably thin gravy) and add some salt as per taste. (Pro tip: That oil separation is the real cue. Rushing this step leaves a raw masala taste.)
Add the fish when gravy starts to boil and let it cook for few minutes. Then add the roasted cumin powder and green and red chilis. Cover it with the lid and leave it for 5-10 mins.
Garnish with coriander leaves and cover it for 5 mins. Transfer Shol Macher Jhol to bowl and serve it hot with steamed rice.