I generally do not use onions when I am making fish, as I have not seen either my mother or my mother-in-law using onions. Though I have now starting making a Kerala style fish curry which uses sliced onions or shallot, never as a ground paste, but the other day I used just that. That is what I am posting today, a fish curry with an onion-tomato gravy.
200 grams boneless fish fillet,
Salt to taste,
½ tsp turmeric powder,
2 tsp of mustard sauce,
2 tbsps mustard oil,
1 medium sized red onion,
Green chillies to taste,
1 inch piece of ginger root,
14-15 garlic cloves,
½ cup of chopped coriander stalks,
1 large chopped tomato,
2 tsps of Kashmiri chilli powder,
1 tsp powdered coriander seeds,
1 tsp powdered cumin seeds,
¼ tsp garam masala powder
1 pinch of mustard seeds,
1 pinch of fenugreek seeds
Wash the fish and apply salt, turmeric powder and 1 tsp of mustard sauce. Let it stand for half an hour.
Grind the onion, green chillies, ginger, garlic and coriander stalks to a fine paste.
Heat the mustard oil till it reaches a smoking point and add the mustard seeds and fenugreek seeds. Once they splutter add the prepared paste and fry for about 3-4 minutes. Then add all the dry spices and cook on a very low flame till the oil separates. I always do this step on a very low flame stirring occasionally and continue with some other task during this duration.
Once the oil separates add the chopped tomato and cook covered till the tomoto softens. Now add salt as required, the remaining mustard sauce and about a cup and a half of water. Let it come to a boil and add the marinated fish.
Cook till the fish is done.
Goes well with rotis as well as plain steamed rice.