To make stuffing add oil to pan aesofetidea, cumin and mustard seeds and curry leaves and let it crackle.. now add onion and let it cook add turmeric powder and mix. now add mashed boiled potatoes and salt and mix well

In a appe pan apply oil put 1 tspn batter and 1 tspn potatoes stuffing and put another spoon of idli batter and cover it and cook