Wash the chana dal twice in running water and then soak it in water along with almonds and red chilies in water for 3-4 hours. Hydrating the dal is very important, to get good vadai.
After the said time, drain all the water from the dal. Take the dal along with the soaked almond and red chilies, in a mixer. Add curry leaves and coriander leaves, raw coriander seeds to the dal. Grind it to a almost smooth batter without adding any water.
Do not operate the mixie continuously. Pulse and grind. If you feel the mixture is getting too dry, add 2 tsps of water at a time and grind again. Remember not to grind the batter smooth. We need little bits and pieces of broken dal here and there.
Transfer the dal to another bowl. Add hing and salt to the batter and mix it well with your hands. Add a teaspoon of ghee or hot oil to the batter and mix. I have missed this step while making vadai, though this didn't change the texture or taste of the vadai, amma says it will keep the vadai crisp and palatable for long time.
Heat oil in a heavy bottom pan. When the oil is hot, drop a small round of batter in to the hot oil, when it sizzles up immediately, then the oil is ready for frying
Wet your left palm, and take a small lemon sized batter in a right palm, place it on the left palm and shape it into a circle. Make sure the circle is thin and in round shape. Transfer the shaped vadai in to your right palm and slide it slowly into hot oil. Take care while doing so.
Fry them in batches, i did 4 at at time. Let the dropped vadai sit for a 30 seconds untouched, then stir the oil with a slotted spoon, let the cook golden brown on both sides.
Remove the vadai with a slotted spoon and drain them on a paper towel. Enjoy the vadai with hot cup of coffee/tea.
The above measurements give 15-18 vadai, when shaped thin and the correct size.