In a wok or skillet heat oil.
Add onions and saute until golden.
Add ginger and garlic and mix well.
Add the spices followed by the tomatoes.
Cook on medium until the mixture is aromatic and oil separates from the sides (6-8 minutes)
Add the potatoes along with some salt.
Cook for about 5 minutes before adding the green beans.
Mix well, cover and cook for about 10-12 minutes stirring every now and then until all cooked.
Adjust the seasonings.Serve hot with Roti or rice and Lentils.