Heat the vegetable oil in a pan, fry the chire over a low flame till crisp and light brown. Keep aside.
Marinate the fish steaks with turmeric powder and a little salt.
In a small bowl, take a little warm water and dissolve the remaining turmeric powder and salt to form a paste, keep aside.
Heat 1 tbsp mustard oil in a pan, shallow fry the fish. Keep aside.
To the same pan, add the remaining oil, when smoking hot, throw in the cumin seeds and 3-4 green chillies. Sauté for a few seconds, allow the cumin seeds and chillies to splutter. Now stir in the the turmeric-salt paste and cumin paste, cook for 3-4 odd minutes.
Lower the flame, add the coconut milk, throw in the remaining green chilies, give it a hearty stir and bring the curry to a gentle simmer.
Gently place the fish steaks in the curry, cook over a medium flame, just a couple of minutes.
Add the fried chire, feel free to throw in some more green chilies if you like it hot. Adjust seasonings.
Allow the curry a standing time of 5-7 minutes. Serve hot.