When I was little, I used to love dosas for breakfast. You could roll them up with ghee and sugar inside and eat them while playing. It was dessert for breakfast! I still love plain dosas. Sometime I make aloo masala to go with, and other times they are great with just some milagai powder and chutney on the side.
Soak dal, rices, and methi seeds for at least 4 hours or preferably overnight.
Grind the dal and rice mixture. Make sure to grind well. You want the mixture to be very smooth. Add salt. Pour the batter into a large bowl, cover and leave it in a warm place to ferment. If it is winter, keep near a heater or in the oven (turned off).
When you are ready to make dosas, take out some batter and dilute with water till you reach the right consistency. It should be thick but easy to spread on the tawa.
Heat a tawa (or flat griddle). Ladle the batter on the tawa and spread into a thin circle using the back of the ladle or a large spoon. Gently grease with oil on the edges and the middle. Cook for a few minutes and flip over to the other side. Cook a few more minutes, transfer to a plate and serve immediately. Dosas are best eaten hot and crispy right off the tawa.