Heat the oil in a pan on medium heat. Once hot add mustard seeds and let them papaya. Then add cumin seeds, let them sizzle.

Then add green chilies and curry leaves. saute for 30 seconds.

Add turmeric powder and hing.

Immediately mix in chopped onions and sprinkle some salt. Cook till onions are soft and light brown.

Add cubed potatoes and remaining salt, sugar and lemon juice.

Mix gently and cook till potatoes are heated through.