Wash and soak the raw rice, idli rice and urad dal together for about 4 hours.
Grind them to a very smooth and thick batter. I used my wet grinder to grind the batter as it yields fluffy batter which results in fluffy seeyam. You could grind it in blender / mixie as well, but make sure you grind it into a thick batter adding just enough water as needed. Add salt needed and mix up the batter well.
In the meantime, heat 1 tablespoon of oil in a pan. When the oil heats up, add the mustard seeds and let it crackle. Now add the asafetida, onions, green chili, curry leaves and salt needed for the onion. Fry them until the onions soften a bit.
Now add the grated / chopped coconut and give it a quick stir. Turn off the flame and let the mixture cool down a bit.
Add this mixture to the ground batter and mix it well.
Heat oil in a pan and gently drop rounded handful of batter into hot oil for deep frying. You could add a few at a time (depending on how big your pan is). Use wet hands to scoop the batter and drop it in oil. It makes it easier to form the seeyam.
Fry them until they are golden brown on all sides and then remove it on a paper towel lined dish.
Serve hot with Chettinad special Kara chutney!