Wash and soak 1 cup of moong dal for 4 hours. Once the dal is properly soaked, drain the water and transfer the dal to a mixer jar.
Add only ¼ cup of water and grind it into a smooth paste.
Then, add 1 boiled potato and grind it again until you get a smooth and creamy batter.
Transfer the batter to a bowl and whisk it for 2 minutes. This will make the batter light and fluffy.
Now, add salt, 1 tbsp cumin seeds (jeera), ½ tsp carom seeds (ajwain), 4–5 finely chopped green chillies, 1-inch grated ginger, some chopped curry leaves, 1 cup chopped onion, and ½ cup chopped coriander leaves. Mix everything well. The bhajiya batter is ready.
Now, slightly wet your hands and take a small portion of the batter in your hand. Heat oil in a pan and carefully drop small portions of the batter into the hot oil to make small-sized bhajiya.
Stir occasionally and fry the bhajiya on medium flame until they become crispy and golden brown. Fry all the bhajiya in the same way.
Moong dal bhajiya is ready. Serve hot with chutney and fried green chillies.