Peel off potoato and cut them in small pieces with mimimum width. Heat Oil in pan, add Sesame, before they sparkle add red chilli, Salt and Asofeotida. Add potato slices and tomato ketchup. Fry poptato till they fully cooked and turns crispy around the pan(Do not deep fry) and keep on turning potatoes to make them crispy from both sides in pan. If required add more oil in little quantities through pan side to make potatoes more crispy. Serve Hot with Nan and chappati