Drain the soaked lentils very well. There should be no water in the soaked dal.
Making dal vada mixture
Then add the soaked lentils in a mixer-grinder or blender.
Without adding any water, grind to a coarse mixture. Some whole chana dal should be there in the mixture. I have not added any water, while grinding.
If you add water, then it becomes difficult to shape them. If you are not able to grind at all, then add 1 to 2 tablespoons water.
Now take the coarsely ground chana dal in a bowl.
Add chopped onions, green chilies, curry leaves and chopped coriander leaves. You can also add chopped ginger.
Season with salt. Mix very well. Check the taste and add more salt if needed.
Now make small or medium sized balls from the mixture.
Flatten them and place them on a plate or tray.
You can use a banana leaf or plastic sheet or a ziplock bag to place the shaped vada.
Heat oil for deep frying in a kadai or pan on medium heat.
Check the oil temperature by dropping a small portion of the batter in the oil. If it comes up steadily & quickly, the oil is hot enough for frying.
Now carefully slid the prepared dal vada in the hot oil.
Fry them for a couple of minutes and then turn over with a slotted spoon and fry the other side. Lower the flame while frying if the oil becomes too hot.
Fry till they become golden and crisp. When the onions on the crust of the vada, look golden, this means the dal vada is done.
Place them on kitchen paper towels to get rid of extra oil.
Fry the remaining dal vada this way in batches.
Serve the dal vada hot with coconut chutney or tomato ketchup.
No onion: If you plan to make dal vada on a festival or a fasting occasion, then simply skip onions. Add a generous pinch of asafetida to mimic the onion flavors.
Soaking: Do not soak chana dal for more than 2 hours. Longer soaking times do not give them a crispy texture.
Consistency: The ground mixture has a thick and coarse consistency. If the batter becomes flowing or runny, then add some rice flour to thicken it.
Shaping: A thick coarse mixture helps to shape the vada easily. For super crispy vadai, flatten them more.
Herbs and spices: Try to add all the spices and herbs to get the best authentic taste and flavor.
Frying temperature: Add a small piece of the ground dal vada mixture in hot oil. If it bubbles, comes up quickly and steadily, the oil is ready for frying. If it stays at the bottom of the pan, the oil is not hot enough - so increase the heat a bit. If it comes up too quickly and fast, the oil is very hot - so reduce the heat slightly.
Scaling: You can easily double or triple the recipe.