Boil the potatoes ( You can pressure cook the potatoes with 2 cups water for 2 whistles or you can boil them in boiling water for 10 mins )
Temper 1 tsp oil, 1 tsp mustard seeds.
Once mustard seeds crackle, add 1 long sliced onion and fry till they are translucent
Next add 1 tsp sambar powder, 1/4 tsp turmeric powder, 1/4 tsp chilli powder, salt and mix them well.
Then add the boiled potatoes and fry for 2 mins in medium flame.
At this stage, add 2-3 tbsp of water if you feel the mix is too dry.
Fry them for 4-5 mins in medium flame till the skin of the potatoes are roasted golden brown. It is done.