In a deep plate mix all the ingredients. Knead to a soft dough. Divide it into 50 equal portions. Shape each portion to a flat smooth round. Press the center lightly with a thumb. Keep aside.
On a high flame, heat oil in a frying pan. Lower the flame. Deep-fry the vadas till dark golden brown in colour. They should be well cooked from inside. Remove, drain and put them on an absorbent paper. Cool and store in an airtight container.