Soked moong dal for 4 hours.
Then drain all water from dal.
Add it into mixer grinder, the add asafoetida, green chillies and ginger. Grind it coarsely.

Take all mixture in a mixing bowl,add all spices mentioned above.
Then add salt and hot mustrd oil.
Give it a good mix and keep aside for 5 minutes.

On bowl or glass wrap muslin cloth Like shown.
Put some moong dal mixture and spread it evenly.

Fry this vada in hot cooking oil, let it cook from both sides.
It will pop up automatically.
Serve hot and enjoy.