Sprinkle turmeric, sugar, lemon drops and salt (as required) over the potatoes and mix well so that the potato cubes are coated with sugar and salt. Leave aside for 5 mins
Heat oil in a Kadai. Add curry leaves and mustard seeds
When the mustard seeds start spluttering, add chopped chillies, chopped onion stir for 2 mins.
When onion becomes pinkish add ginger & garlic. Stir for 2 mins. Now add the potatoes and mix well.
Cover and cook for 5-10 mins. Keep stirring at intervals
Garnish with coriander and serve with puris/chapattis