Wash and soak rice in four cups of water overnight. Drain and grind to a fine paste along with scraped coconut using a little water. Add salt and enough water to get milk like consistency. Heat a non-stick pan/dosa tawa and pour just enough oil to grease it.
Sprinkle some water and wipe clean pan/tawa with a muslin cloth. Stir and pour a ladle full of batter, taking care that it spreads in a thin, even layer. Cover and cook in its own steam for two minutes. Remove carefully, fold into a triangle and serve immediately