Heat ghee or oil in a pan on medium flame. Add mustard seeds, urad dal, chana dal and let the seeds pop. Then add curry leaves, chopped green chilli and ginger — sauté briefly until aroma rises.

Add rava (semolina) to the pan. Roast on low flame, stirring often, until the rava turns light golden and smells aromatic. Turn off heat and let it cool for a few minutes.

In a large bowl, mix curd, water, salt and chopped coriander leaves. Stir well to combine without lumps.

Once the roasted rava has cooled a bit, add it to the curd mixture. Mix thoroughly until you get a smooth batter. If batter feels too thick, add little water to adjust consistency (should be like idli batter).

Cover the batter and let it rest for about 15–20 minutes so the rava absorbs moisture and softens.

Just before steaming, sprinkle fruit salt (or baking soda) over the batter and gently fold to mix — this helps the idlis turn soft and fluffy.

Grease the idli mould plates lightly with ghee or oil. Pour the batter into moulds. Steam in an idli steamer or pressure cooker (without whistle) for 12–15 minutes or until a knife/skewer inserted comes out clean.

Let the idlis rest a minute before removing them from moulds. Serve hot with coconut chutney or sambar.