Chop potatoes into small cubes and keep them aside. 

Heat oil in a pan. Use a non stick pan if you are calorie conscious as less oil can be used. You can even use a well seasoned cast iron pan. Other pans might require some more oil so add accordingly.

Add mustard seeds. Once mustard seeds are crackled, add cumin seeds and curry leaves.

Add the potato cubes and mix well.

Cover and cook on low flame for 10 mins.

Stir in between and after about 5 minutes add turmeric powder, pepper powder, salt and mix well.

After about 10 mins check whether the potatoes are soft. If they are then increase the flame to medium-high and keep stirring for 5 to 7 minutes till the potatoes are browned in the edges.

Once the potatoes are roasted, garnish with coriander leaves and turn off the gas.

Serve with curd rice / sambar rice / rasam rice !!!