Heat the oil in a pan. Add cummin seeds and stir till they splutter. Add the cubed potatoes, and saute till they are evenly cooked. Add the turmeric,red chilly powder in a spoon of water, mix it evenly and add to the sauted potatoes.Add half a cup of water. Cook on a low flame with a closed lid, till all the water evaporates. Garnish with fresh coriander leaves. Add sea salt to taste.