Wash and soak chana dal in one and a half cups of water for an hour. Drain and keep aside.
Heat oil in a pressure cooker, add asafoetida, mustard seeds, cumin seeds, curry leaves, ginger, onions and sauté till the onions turn light brown.
Add chana dal and chopped green chillies. Stir. Add red chilli powder, turmeric powder and salt. Mix and continue to sauté for three to four minutes.
Add doodhi pieces and mix. Add garam masala powder and chopped coriander leaves.
Put the lid on and pressure cook for five minutes. Open lid when pressure is fully released and serve hot with chapatis.