Take a deep pan with a thick bottom. Turn on the flame and add oil.
Take a pressure cooker of 3 lt capacity.
Add mustard seeds and cumin. Once they start spluttering, add onion and green chillies.
Sauté. Cook till the onions turn transparent.
Add turmeric and salt.
Add curry leaves.
Now add the bottle gourd pieces and cook.
After 5 mins, add the spring onion bulbs and greens and stir carefully or just try to toss.
Add the red chilli powder, jeera powder, coriander powder, and toss.
Cook for 5 mins.
Squeeze the pulp for the soaked tamarind and add it to the gravy. Add some more water to maintain the consistency.
Bring the contents to a boiling state.
Close the cooker with the lid. Cook till one or two whistles.
Let it cool and garnish with chopped coriander.