Firstly, soak 1 cup alsanda for 5 hours, and drain off the water.
Transfer the alsanda into mixer jar, add 3 chilli, 1 inch ginger and 1 tsp cumin.
Pulse and grind to a coarse paste.
Transfer the batter to the bowl. Add ½ onion, 2 tbsp spring onion, few curry leaves, 1 tsp salt, pinch hing and ¼ tsp chilli powder.
Squeeze and mix well, making sure everything is combined well.
Now wet your hand or grease your hand and pinch a ball-sized mixture.
Flatten slightly with your palm, make sure to keep the edges thin compared to the centre.
Drop the vada into hot oil, keeping the flame on medium.
Do not touch the vada for 2 minutes; otherwise, there is a chance for the vada to break. Stir occasionally, and fry on low to medium flame. Fry until the vada turns golden and crunchy.
Drain off and keep aside. Make sure to fry on low to medium flame, or else the vada will turn crispy from out and remain soft from the inside.
Finally, Alsanda Vada Recipe tastes great for up to 2 days when stored in an airtight container.