1. Rinse the urad dal in cold water until the water runs clear. Soak the dal in water for at least 4 hours or overnight.

2. Drain the dal and add it to a blender or food processor. Add a little water and blend until you have a smooth batter. The batter should be thick and fluffy.

3. Transfer the batter to a large mixing bowl. Add rice flour, chopped ginger, chopped green chilies, chopped cilantro, cumin seeds, and salt. Mix well.

4. Heat oil in a deep frying pan over medium-high heat.

5. To shape the vada, wet your hands with water. Take a small amount of batter in your hand and make a hole in the center with your thumb.

6. Carefully drop the vada into the hot oil. Fry the vada until it turns golden brown and crispy on both sides.

7. Remove the vada from the oil with a slotted spoon and drain on a paper towel.

8. Repeat the process with the remaining batter.

9. Serve the medu vada hot with coconut chutney or sambar.

Note: You can also add finely chopped onions, grated carrots, or grated coconut to the batter for more flavour and texture. Adjust the number of green chillies according to your taste preference.