Heat 1 tsp oil in preferably a large non-stick wok. Splutter the mustard seeds. Add the udad dal and fry till golden brown, and then saute the dried red chillies and asafoetida for a few seconds.
To this, add 4 1/2 cups of water. In the water, put in the coconut, jaggery and salt. Bring it to a rolling boil.
Keep the flame on sim, and add the idli rava little by little with constant stirring to avoid any lump formation. Stir the rava well, and cover and cook for 5-6 minutes like how you would make an upma.
Rice rava cooks faster than semolina rava. All the water must get absorbed and the resulting mass shouldn't stick to your fingers.
Remove the 'upma' onto a big dish / thali and cool off for 5-10 minutes. Once cooled, take a big handful of upma and shape it into ovals / spheres, dipping fingers into water, to prevent from sticking.
You will get roughly 14-15 such palm sized kozhakattais from 1 1/2 cups of flour. Arrange this in a steamer and steam them for 10 minutes.
Serve hot straight out of the steamer with some spicy coconut chutney.