First, marinate the fish with a pinch of salt and turmeric, using your bare hands. Allow it to marinate for 10 minutes.
Next, heat a pan. Pour in the oil and heat it up, then carefully add the fish to the pan.
Fry the fish by flipping it to the other side, ensuring it is lightly fried.
Take out fried fish and keep them on a separate plate.
Similarly, lightly fry the eggplants and add a pinch of salt and turmeric while frying. Take out lightly fried eggplants.
Add potatoes to the cooking pan and then kalonji. Stir well.
Incorporate the ginger-garlic and onion paste and fry it. Then, add the powdered masalas such as turmeric, red chili powder, coriander powder, and roasted cumin powder. Add half a teaspoon of salt.
Sauté it well for 5 minutes and then add water.
Once the oil separates from the masalas, add water to make the curry. Adjust the amount of water to achieve the desired soupy consistency.
Add the fish and eggplants to the curry and let it simmer for 10 minutes.
Finally, add the green chilis and roasted cumin powder as a garnish.
Aloo Begun Macher Jhol is ready and transfer it into a serving bowl.
Serve it with steamed rice.