Take a big bowl and add 1 cup of dry mung beans. Soak it in the water for 4-5 hours. Then, strain and rinse the soaked mung beans 2-3 times with clean water. The soaking time and sprouting time of the mung beans are not included in the preparation time of this recipe.
Transfer the beans to a damp muslin cloth. Bring the edges together, fold tightly and cover the beans with the cloth. Cover the bowl with a lid and keep it in a warm and dark place for sprouting. It will take around 24 hours.
Take a blender and add sprouted mung beans, onion, ginger, garlic cloves, green chilli, fresh coriander leaves, mint leaves, roasted cumin powder, red chilli powder and salt. Add 1/3 cup of water and blend it at high speed. Grind it to a fine smooth paste.
Now besan (gram flour) and 1 cup of water and mix it well. Prepare a lump-free batter. The batter should be of medium consistency, neither thick nor thin.
Place a pan (preferably a non-stick pan) on the stove. Grease the pan with ¼ tsp of ghee on medium flame and rub it with tissue paper.
Now pour the chilla batter with a ladle on the pan and gently spread it thin like dosa. If you find difficulty in spreading the chilla batter, then add more besan to the batter. Add 1 teaspoon at a time.
Add 1 tsp of ghee to the centre and around the corners of the chilla. Cover and cook it for 2 minutes on low flame until it becomes crisp and golden from one side.
Flip it to the next side and cook it for 1 minute.
Sprouted mung chilla is ready to serve. Serve hot chilla with green chutney and tomato ketchup.