Cut parwal into halves. Wash well. Cut potatoes into medium size cubes and wash well. Dry up and rub salt and turmeric powder into them.
Heat oil in a skillet and fry the parwal in two batches. Remove and set aside. Make paste of cumin and coriander powder.
To the remaining oil in the cooker, add a bay leaf. Add potatoes and fry well in the same oil. After potato is fried, add the coriander and cumin paste. Add the crushed ginger. Stir and further add turmeric, red chili powder, and garam masala powder. Stir and fry for about 1 minute.
Add the fried parwal, salt and sugar and a cup of water. Cover and cook till potato and parwal pieces are all cooked through. Pour ghee on top of the parwal curry. Serve hot