Heat oil in a pan.

After it heats up add mustard seeds and 4-5 curry leaves. Let them splater.

Add onions, turmeric powder and salt and fry till the onions become soft.

Add in the potatoes.

Add in red chilli powder and fry for 2-3 mins.

Then add the dahi and curry leaves and cover and cook for 10 mins more stirring occasionally on medium heat.