Wash and soak all lentils for 2 hours. Drain and rinse them well.
Keep aside 2 to 3 tbsp of the soaked dal separately.
Pulse red chilies (if using) in the grinder. Then add the rest of the lentils to a grinder. Pulse to a coarse paste without adding any water.
Transfer this to a mixing bowl. Add the lentils that we kept aside, garam masala powder, green chilies, ginger garlic paste, curry leaves, coriander, onions and cumin. Mix well.
The mixture has to bind well. Check by making a ball and then flatten to see if it holds shape. Otherwise, take about ¼ cup of this mixture to the blender and blend again. Mix everything well.
Taste test and add more salt if needed.
Heat oil in a deep pan for frying.
Pick up small portions, shape them to small balls, and flatten on a greased sheet. You will be able to make 10 vadas out of this.
Check if the oil is hot by dropping a small portion of the mixture. It must rise slowly without browning.
Transfer the moong dal vada on to your greased fingers and drop in the hot oil gently. You can drop 2 to 3 vadas in one batch, depending on the size of the pan.
Fry them on a medium flame. Do not disturb for 2 minutes otherwise they will break.
After 2 mins, flip the dal vada around to the other side. Fry till golden and crisp. Remove and drain them on a kitchen tissue.
Repeat making vadas and frying till you finish the ground mixture.
Serve moong dal vada hot with your favorite chutney or with tea.
Preheat air fryer for 10 minutes at 180 c or 360 F for 10 minutes. Place the dal vadas on the rack and spray with oil. I do not spray at this stage.
Air fry for 15 to 17 minutes until golden and crisp, if needed turn them to the other side after 10 minutes. Do not handle them when they are still soft.
Once done, brush them with ghee and serve hot.