In a mixing bowl add mashed potatoes and the remaining ingredients for potato balls.Mix until everything is combined.Make small round balls from the mixture and set them aside on a plate.
In another mixing bowl add buckwheat flour, salt, and cumin seeds. Slowly add water and whisk to make a lump-free batter.
Heat oil in a wok or pan. Dip one ball at a time in the batter and place it in the heated oil. Furthermore, dip few more balls in batter and transfer them to the oil.
Fry from both sides until brown and crispy.Drain on paper towel.