1) Boil Sweet potato in pressure cooker until 2 whistles.
2) Peel the boiled potato and cut in to small bites.
3) Heat up 2 tbsp Oil, add cumin seeds, bay leaf, green cardamom. ginger paste and cook ginger paste for 1 minute.
4) Lower down the heat and add all dry spices, mix and cook for 2 minutes.
5) Add water, mix and cook for 2 minutes.
6) Add cubed sweet potato, mix, cover and cook over medium heat for 5 minutes.
7) Garnish with chopped coriander leaves and serve with hot roti or rice.