Soak Bengal gram in water and keep aside, till soft enough to be ground.
Peel the banana flower stalk (each layer will have many tiny flowers). Remove the outer layers, till you find no more tiny flowers. This last bit inside should be chopped into fine pieces.
Take water in a vessel, add a spoon of curd and immerse the chopped pieces in the mixture. Keep aside for half an hour to remove any sap.
Wash it well and boil it in water with little turmeric powder and salt.
When done, remove all remaining water and keep aside to cool.
Squeeze out any remaining water.
Grind Bengal gram or channa dal, green chillies, ginger, garlic, cinnamon stick, cardamom and cumin seeds together.
When done, add the banana flower pieces to the mixture.
Make tiny balls and flatten them with hand to the shape of vadas.
Heat a little oil in a pan.
Dip these in beaten eggs and roast both sides in oil, until brown.
*The banana flower is the flower of the banana tree. If you open the inside of the flower stalk, you can see small flowers that would turn into banana.