Marinate the fish with salt, a few drops of oil and a pinch of turmeric powder, keep aside.
Heat the oil in a pan, shallow fry the fish till light brown. Keep aside on a kitchen absorbent towel.
To the same pan, throw in the kalonji and 2-3 green chilies. Allow them to splutter.
Add the pumpkin slices, fry for 3-4 minutes over a high flame.
Add the tomato puree, ginger paste, turmeric powder, red chili powder and salt, cook till the tomatoes are cooked and oil starts to release from the masala.
Add 1/2 a cup of warm water and let the curry simmer patiently till the pumpkin is perfectly cooked.
Gently add the fried fish, cook for 3-4 odd minutes.
Adjust seasonings, throw in more green chilies if you like it hot.
Serve hot with rice.