My favourite dosa. is easy to mix and can be used instantly.
Take all the ingredients in a bowl and mix with water make a loose batter. It should be runny you can also add 1/4 tsp soda.
Take a dosa pan apply oil to the pan and when it gets heated take a big ladle full dosa batter and pour it from the outside of the pan all around to form a even round and leave oil all round the dosa.
Fry it on both the sides till nicely done. It takes a little practice to get it perfectly like in the hotels. But you will succeed to make as good ones.
Don't make the batter too loose or it will stick to the pan. All the best.