Smear the fish with a little turmeric powder, salt and 1 tsp oil.
Add a little water to the cumin paste and remaining turmeric powder and make a paste.
Heat 2 tbsp oil in a pan, shallow fry the fish steaks. Keep aside .
Into the same oil, throw in the fenugreek seeds, allow the seeds to turn dark brown. Carefully discard the burnt seeds.
Now add the onion paste, ginger paste, tomato purée into the same pan, sauté over a medium flame till the raw smell of onions is gone and the tomatoes are cooked.
Add the cumin - turmeric paste, continue to cook till oil is released.
Add the bottlegourd slices, sauté for 4-5 minutes. Add 1.5 cups of warm water, cover and cook over low flame until the bottlegourd is tender.
Add the fish pieces and green chilies, cook for another 5-7 minutes. Switch off the flame.
Finish with chopped coriander leaves and a generous drizzle of mustard oil. Allow to rest for 10 odd minutes. Serve with piping hot rice.