Soak the urad dal in a large bowl of water for 2 hours.
Then drain the dal and transfer it to a blender or food processor.
Process until coarsely ground, then set aside.
Put the rice in a blender or food processor and process until ground.
Then transfer to a large bowl and add the dal and cumin.
Mix, and add enough hot water to make a batter. Season with salt.
Oil a curved, deep tawa or a heavy-based frying pan (skillet) and heat it.
When hot, pour in a ladleful of the batter and spread it over the base.
Cook over low heat for about 2 minutes, or until golden brown, then flip the pancake over and cook the other side for a further 2 minutes, or until done.
The pancake will be thicker in the middle.
Transfer to a serving plate and serve hot with a spicy chutney. Make the others in the same way.