Soak chana dal in water for an hour and then drain the water. Retain this water. (You can soak for 10-15 more if you want but make sure you let it soak for a minimum of one hour else chana dal won't cook properly.)
Cut green chili lengthwise in two pieces and deseed it.
Heat a pressure cooker, add ghee, and then add cumin seeds.
When cumin seeds start to splutter, add hing and green chili pieces.
Add chopped onion and sauté till it turns translucent.
Add grated ginger and saute for half a minute, and then add chopped tomatoes.
Add haldi and red chili powder, and sauté till ghee starts to separate from masala.
Add chana dal and sauté for half a minute, and then add chopped lauki.
Add salt and garam masala powder and mix properly.
Add half to 3/4th cup water (water in which chana dal was soaked) and cover the pressure cooker with a lid.
Cook on medium-high heat for about 3 whistles.
Take off the lid after pressure settles and then add chopped coriander.
Mix properly and serve hot with chapatis.