Rinse chana dal in enough water and soak it for 3 hours.
Method
Drain all the water from chana dal using colander and transfer it to a blender/mixer. Add green chillies and ginger pieces.
Grind them together to a coarse paste such that some lentils are intact and unbroken. Transfer it to a bowl.
Now add finely chopped coriander leaves, curry leaves, rice powder, salt and hing(asafoetida). Mix everything together.
Take a lemon sized mixture and pat it like vada on your palm. You can get a batch of such vada ready.
Next heat enough cooking oil in a heavy bottom wok. As it gets heated, slowly drop vada in to oil and deep fry till they turn brown. Remove from oil once done. Drain over tissue paper.
Repeat the process till all mixture is done. Yummy and crispy masala vada is ready to serve as tea time snack.
Notes
Do not add water while grinding the soaked chana dal.
You can replace rice powder by rava or semolina too. It gives crispiness to vada.
You can include greens like dill leaves too.
Store in air tight container to extend crispiness for long.