Sesame oil is a must for this recipe (unless you are making Kerala style fish curry for which case you can use extra virgin coconut oil).  Heat sesame oil in a pan, and when it is moderately hot, add methi seeds and when they turn slightly brown, add the curry leaves and give a quick stir.

Add the chopped shallots and fry till they brown a bit.

Add chopped garlic and fry till they sweat a bit (do not brown them otherwise the curry will turn bitter).

Add chopped tomatoes and pearl onions and some salt (to speed up the sauteeing process) and fry till the tomatoes are cooked well and oil oozes out.

Add sambar powder (or substitute) and turmeric powder and fry for couple mins.

Add 2 cups water, tamarind juice and mix well and adjust salt.

Cover and boil for about 10 to 15 mins till the curry gets cooked well.  Check for salt now - the curry should be a bit salty/ soury to taste than normal.  The salt and sourness level will balance out when you add and cook the fish.

Add the fish (spread/ space them out in the pot) and cover and cook for about 5 mins.  Open the lid and give a gentle stir (you can also lift the pan and give a gentle shake).  Key is not to stir too much and break the fish.

Continue cooking without lid for another 5 mins or so and finish off by adding one tbsp sesame oil and giving a gentle stir.

Throw the whole uncooked raw okras into the curry just before serving!