Half the potatoes and parboil them in water for about 15 mins.
Transfer the potatoes into a bowl with cold water to cool them down, drain the water and then slice the potatoes into bite sizes.
In a wide bottomed pan, heat the oil, once the oil is hot, add in the cumin and black mustard seeds. Heat until they splutters.
Lower the flame, then add in the turmeric powder and the curry leaves and sauté.
Then in go the chopped ginger, garlic and green chillies.
Cook them nicely, then add the potatoes and stir well so that the turmeric ginger garlic mash coats the potatoes evenly.
Sprinkle a little water, season with salt, cover and cook for about 10 mins. Its fine if the potatoes catch a little, the browned roasted potatoes will lend their own unique flavour to the dish. Take off heat once the potatoes are squishy and cooked.