Take cleaned fish pieces in a bowl and add salt and turmeric. Then rub them on both sides of the fish well and allow to marinate for 10- 15 minutes.
Fry the fish pieces on both sides in hot oil until they are golden brown.
After that, remove the fish pieces and add the whole spices to the remaining oil.
Once the oil turns fragrant, add the chopped onion and cook until the onions turn soft.
After that, add onion paste and cook it thoroughly until the raw scent is gone.
Then, add the ginger and garlic pastes and cook for a short while.
Add the green chillies next, then the spice powders such as cumin, coriander, turmeric and red chilli powder. If necessary, add a little water now to prevent the burning of the spices.
When the spices are well combined, add tomato paste and cook until the raw smell disappears.
At this time, stir in the sugar and salt.
When the masala is thoroughly cooked, you will see that the oil begins to separate.
After that, add 2 cups of warm water and let the gravy simmer for a short while. Now taste the salt and make the necessary adjustments.
Add the fried fish pieces in the gravy. Cover the pan and cook under low flame for few more minutes.
Switch off the flame and give a standing time of 5-8 minutes before you serve the fish kalia.