Cook potato in pressure cooker. Meanwhile, chop onion and mince ginger and garlic. Chop carrot well (using food processor). Heat a nonstick pan and add butter. Add ginger garlic and fry till browned. Add onion,carrot,garam masala, chilly powder and salt and fry for 3-4 minutes on low flame. Mash the cooked potato and add it to the pan. Mix well and remove from flame. powder corn flakes and keep it in a plate. Beat egg in a bowl. (Half of the beaten egg can be added to the carrot mix.) Take lemon sized balls from carrot mix and make the desired shape, dip well in egg and then coat with corn flakes powder and keep them in a plate.(This proportion will make about 6 cutlets). When all set to fry, heat oil in a pan and arrange all the cutlets in the pan and shallow fry till both sides are golden brown. Serve hot with tomato sauce.