Heat oil in a pan, add the mustard seeds and allow it to splutter.
Add the sliced onion and saute it until its golden brown.
Add the chopped ginger, garlic, green chillies and fry it for 2 minutes. :-Try to add fresh ginger and garlic instead of paste.
Add the tomato and fry for 2 minutes.
Add the turmeric, coriander and cumin powder and fry for 1 minute.
Add the yogurt and stir it well.
Add 150 ml of boiled water, salt and mix it all well and let it all boil on medium heat for 2 minutes.
Add the cleaned fish (you can cut your fish into half if you like).
Add garam masala and mix it all well and cover it with a lid and let it cook on simmer for 12 minutes.
Add lime juice, mix it again and add the crushed pepper.
:-Do not use thin powder.
Cover it again and simmer it again for 5 minutes.
Leave enough gravy unto your desire.
Then turn off your cooker and add the curry leaves.
:- Ready to serve now!!!
:-Its a good combination with rice or chappatis.
Note: Preparing this Karimeen Masala dish with Karimeen found in backwater of Kumarakam will enhance the taste of the curry.