Heat one tablespoon of oil in a pan. Add cumin seeds. When they change colour add onion, ginger and green chillies and sauté till the onions are golden brown. Add diced potatoes and mix. Mash peas slightly and add to the potato mixture. Add salt, chaat masala powder, garam masala powder and mix. Cook for two to three minutes. Remove into a bowl and mash a little. Let it cool.

Heat sufficient oil in a kadai. Take one patti, rub it with water. Place the mixture on one end and fold it in triangular shape. Seal the edges properly. Deep-fry in hot oil till golden. Remove and place onto an absorbent paper and serve hot.