There's no recipe for this one, because it's made of store bought batter. That's one good thing about Bombay. Every store around here sells freshly ground idli and dosa batter, so you never need think about soaking and fermenting things for 2 days and what not.
It's pretty much instant. Buy the batter, drop a couple of tbsp on a heated nonstick griddle, spread it out as thin as a crepe, add a bit of oil, let it brown, then fold. Still to perfect the technique but the initial results were not too bad.