Cut your fish into fairly large chunks – mine were about 2*2 inches. Sprinkle them with the turmeric powder, salt, and juice of one lemon and set aside.
Warm oil in your pan on medium high heat and roughly chop your tomatoes.
When the oil is hot add the seeds i.e. fenugreek, and kalonji and curry leaves and just wait for them to splutter and become aromatic.
Now add your garlic, let it cook for 30 seconds and then add your tomatoes, salt, chili powder, and chili flakes.
Mix well and cook the tomatoes on high heat, stirring constantly until they get dark red and caramelly looking. This takes me about 10 minutes in a large wok.
If you are up for it then taste your spice mix, adjust seasoning if necessary, then place your fish pieces in the pan and cook for 3 minutes.
Carefully flip and let the fish cook through, another 2-4 minutes depending on the fish, a piece pressed will flake easily.
Drop the heat and add the butter, kasuri methi, fresh pepper, give it a gentle stir, adjust seasoning.
Garnish with cilantro, ginger, chilies and dig in!