Cover the rice and dals in separate vessels with cold water and leave to soak for 2 hours.
Drain the dals and rice.
Put the rice, toovar dal, chana dal, urad dal, red chillies and asafoetida in a blender with a little water and grind to a coarse batter.
Add the remaining ingredients except the oil for deep frying. If the batter is very thick, add a little water.
Heat the tava. Spread a little batter on the tava and drop a little oil around the edge of the batter. Allow to cook for a few minutes. When brown spots appear on the edge, turn the adai and cook on the other side.