Heat oil in a heavy bottom sauce pan heat the oil over a medium flame. Add the nigella seeds and green chillies. Fry for 7-8 seconds and add the onion and saute for 1-7 mins. Then add the peeled potatoes. Mix well and fry for 5 minutes.

Bring to a boil and simmer with the lid on for 15 minutes. Stir halfway through cooking. Add a few more chillies (if you like it spicy) and simmer for 2 minutes. Add a little more water if it gets too dry.