Add a teaspoon of salt to the potatoes and set them to boil until fully cooked
Once boiled, remove them in a mixing bowl and add the turmeric powder, chilli powder, salt to taste and a teaspoon of the chopped coriander
Toss them in the bowl so that the spices coat the potatoes well. Also, make sure that the edges of the potatoes are slighted roughed up
Heat a pan with oil and add the mustard seeds, curry leaves and chillis, if using
Once the seeds splutter, add the potatoes and toss them for couple minutes
Lower the flame and add the sambar masala. Mix well so that it coats the potatoes well
Toss and cook for another 5-7 minutes until you have achieved the desired crust on the potatoes
Remove from flame, add the chopped coriander and lemon juice. Mix well
Serve the the roast potatoes with sambar masala hot! Enjoy!