Boil the Arbi till soft (2-3 whistles in pressure cooker). Drain and peel the skin. Mash them well and mix with all the following ingredients except oil.
Wet your palm and shape the mix into cutlets. Coat with the rice flour and chill for an hour in the refrigerator.
Heat oil in a pan and deep fry the cutlets till golden brown on both sides. Drain on a kitchen towel and serve them hot with any chutney or sauce.