Heat ghee in a pan, add mustard seeds, cumin seeds, chana dal and urad dal. Once the seeds start to splutter, add ginger, green chilies and curry leaves, cook for about 1 minute.
Stir in the ground oats, quinoa and sooji. Cook on low flame until lightly toasted and fragrant. Remove into a mixing bowl and cool slightly.
Next add the grated carrot, green peas, cilantro, buttermilk and salt. Mix well and set aside for about 10 minutes.
The mixture gets quite thick, so add a little bit more buttermilk or water to thin out the batter to get to idli batter-like consistency. Stir in the baking soda just before making the idlis.
Lightly grease the idli mould and divide the batter evenly among the idli plates. Steam for 12~15 minutes in a pressure cooker (without whistle) or in a steamer. Turn off the heat and let rest for at least 10 minutes for the idlis to cook completely.
Serve hot with your favorite chutney. I served my idlis with this quick tomato-peanut chutney and idli podi.