• Pat dry the fish fillets and rub it with salt and turmeric powder. Keep it aside for 10 to 15 minutes.
• Simultaneously, slice the eggplant into thick slices, layer it on a colander and sprinkle salt over it. Let it aside for 10 to 15 minutes. This will release the moisture and avoid absorbing too much oil when you prepare the dish.
• In a bowl, whish turmeric and chili powder with little water and keep it aside to be used later.

Frying the fish properly is important:

• Make sure the pan is hot enough before you pour the oil, and then give a few seconds to heat the oil.

  Then very gently layer the marinated fish and don't move it for 1 minute. Let it fry and then gently flip and fry for 1 minute.

  If the pan is hot enough and the oil is hot, the fish will not stick to the pan and will flip nicely.
• Heat a heavy bottom skillet and pour mustard oil. Heat the oil and then sprinkle nigella seeds. Let it sizzle for a few seconds and then scatter the eggplant. Cook the eggplant for 3 to 4 minutes by tossing and turning.
• Pour the spice mix that you had kept ready and mix it around. Cook the spices for a few minutes.
• Pour hot water and gently layer the fried fish and let it simmer for 5 minutes.
• Make a slurry of flour and water and pour it to the pan. That will thicken the gravy. Check for salt at this stage and add more if needed.
• Simmer for another 2 minutes and Ilish Tel Jhol is ready.