Soak the moong and chana dal in warm water overnight or for at least 5 to 6 hours.
Once the dal has soaked well, drain the water and grind using very little water to make a coarse thick vada batter.
Transfer the batter to a mixing bowl. Add chopped onions, chilies, ginger-garlic paste, asafoetida and salt to taste. Mix well to combine and allow it rest for 10 minutes.
Heat Freedom oil for frying in a deep frying pan. Once oil is hot, make small balls of the Moong Dal Vada batter and drop in the hot oil carefully. Deep fry the vadas on medium heat till theyturn golden brown and crispy.
Place the moong dal vada onto a plate with an oil absorbent paper and drain the excess oil. Serve warm.