Add doodhi, chana dal, and turmeric powder in a pressure cooker with 3 cups water. Close pressure cooker and cook on high pressure for 1 whistle. Lower heat to simmer and cook for 3 more minutes. Turn cooker off and allow pressure to release naturally.
Heat oil in a large saucepan. Add cumin seeds and red chillis and fry till seeds splutter. Add the ginger and garlic. Fry for 1 minute. Add the cooked dal, salt, sugar, and chilli powder. Bring to a boil, reduce heat and cook 5 minutes. Serve hot.