Rohu fish fillet as per your serving size (I used 8)
2 medium potato, cut into wedges
1 medium tomato chopped
1 tbsp ginger grated
1 tsp cumin seeds freshly roasted
1 tsp coriander seeds freshly roasted
1 tsp chilli powder
1 tsp turmeric powder
1/2 tsp sugar
3-4 slit green chillies as per taste
1 tsp onion seeds or kalonji
Fresh coriander leaves for garnishing
Mustard oil for frying the fish and 1/2 tbsp for gravy if required
Salt to taste
Wash and clean the fish. Apply little salt and turmeric and keep aside for 20 minutes. You can keep it for longer as well. I applied it in the afternoon and kept it in the fridge till I made the gravy in the evening. However, take the fish out and bring it back to room temperature at least 1 hour before frying.
Make a paste with the roasted cumin seeds, coriander seeds, ginger, chilli powder, and turmeric powder with a little water. Keep aside. This is usually done on a silbatta or mortar and pestle for the ultimate taste. I had to do it in my regular grinder like in most modern homes!
Heat oil in a deep bottomed pan with a lid and bring it to smoking point. Add the fish pieces, leaving enough space for it to be fried golden on all sides. Do not overcrowd the pan. Cover the pan with the lid while frying to avoid spillage of oil on the outside as well as on your face and hands. Also, keep adjusting the heat so as not to burn the fish. Remove from heat and keep aside.
In the same pan, add any extra oil if required. Now add the kalonji and slit green chillies and let it splutter. Fry the potato wedges till golden. Now add the chopped tomato and continue frying on a medium heat till soft and mushy. Add the ground paste and rinse the grinder with a dash of water and add it to the pan. This will ensure that your masala does not stick to the pan without adding any additional oil and also saves you from wasting the residual masala. Take care while stirring the masala now as it might break the potatoes. When the oil starts leaving the sides of the pan, you will know that your base is ready. Now add the salt and sugar as per your taste and 1 cup of water. Bring it to a boil and then add the fried fish. Cover and cook on a medium flame till gravy thickens to desired consistency. Pick 3-4 potato pieces in a bowl and mash them with the back of a spoon. Put it back into the pan and stir. Check for seasoning and remove from heat. Garnish with fresh coriander leaves and slit green chillies and serve hot with steamed rice.