I soak chana dal for 6-8 hours in clean water. Next wash them nicely and drain the water. Next keep ginger, garlic, curry leaves, green chillies and dry red chilies ready. Take out a handful of chana dal and keep aside.
In a blender jar put rest of the dal, salt, turmeric, ginger pieces, garlic cloves, green chillies, dry red chilies, few curry leaves, hing and ajwain.

Use minimum water and grind to make a coarse mirture.

Do not make the batter runny. In case your batter becomes runny don't worry you have back up of dal kept. Moreover if you add the sabut dal into your vada batter, it gives a nice crunch upon frying.

Now take a mixing bowl, put into it sliced onion, few curry leaves and sabut soaked chana dal. Then add the vada batter.

Mix all well. Now add rice flour,it adds to the crispiness. Add little salt, cumin seeds and red chilli powder. Mix all well. An even vada batter is ready.

Now as you are preparing the vada batter side-by-side heat oil for deep frying in a kadhai. Now wet your hands. Take a lemon size portion of the mixture and flatten it. Make it thin. As because, if you keep it bulky, it won't become crispy. Make a round shape. Now carefully leave into the medium hot oil for frying.

Never fry at high heat it will change colour but will not get cooked. Never fry at very low heat. It will absorb lots of oil. So fry at medium heat. As it's cooked you can little bit increase the flame for a nice colouration.

Crispy chana dal vadas are ready... Serve with garma garam chai...