Wash the idli rice and urad dal separately under running water.
Soak them in water for about 4-6 hours.
Drain the water from the soaked rice and urad dal.
Grind them separately to a smooth batter using minimal water. The urad dal batter should be fluffy.
Mix both batters together in a large bowl and add salt. Allow it to ferment overnight or for at least 8 hours.
While the batter is fermenting, steam or blanch the chopped spinach until it wilts.
Blend the wilted spinach into a smooth puree.
Once the batter is fermented, add the spinach puree, grated carrots, and cumin seeds. Mix well to ensure even distribution.
If the batter is too thick, add a little water to achieve an idli batter consistency.
Grease the idli plates with a drop of oil.
Pour spoonfuls of the batter into each mold.
Steam the idlis in a steamer for 10-12 minutes or until a toothpick comes out clean when inserted into the idlis.
Allow the idlis to cool for a few minutes before removing them from the molds.
Serve these nutritious Spinach Idlis with a side of coconut chutney.