Wash and soak bengal gram dal and tur dal for 2 hours.
Take tender banana flowers, chop it and keep in diluted buttermilk until use to prevent discoloration.
After 2 hours, drain the water completely from the dal, add green chilies, fennel seeds, fried gram, salt and grind in a blender for 2-3 seconds.
Drain the vazhaipoo and to the dal mix and grind it coarsely for 3-4 seconds, leave a gap of 3 seconds and then grind again. The vazhaipoo vada batter should be slightly coarse. Taste the batter to check for salt.
Now add finely chopped onions, finely chopped coriander leaves and few curry leaves. Mix everything well.
Take a lemon-sized ball of the batter, flatten it with your hands and form into a disc.
Heat oil in a kadai
Once the oil is hot, reduce the temperature to medium. Drop the prepared discs/patties into the oil gently. Fry both sides until brown.
Remove from oil with a slotted spoon and drain excess oil on a paper towel.
Repeat the same process for the rest of the batter.