I love Paper thin crispy rava dosas. This dosa does not need any fermentation and could be prepared quickly. I took the proportion from lathas blog and its pretty accurate.
Rava - 1 cup
Rice flour- 1/2 cup
All purpose flour - 1/2 cup
Water - 6 cups
Chopped Green chillis - 3 to 4
Whole/Coarsely ground black pepper - 1 sp
Tempered Mustard - 1 sp
Cumin - 2 sp
1 or 2 Chopped onions
Oil - For making dosas
Mix all ingredients together ( except onions). Let it rest for 1 hour minimum (Rava tends to absorb the water). The batter will be a very thin pouring consistency, like butter milk.
Heat the tava, once it is well heated up sprinkle the onions on top (This way the onions bind well with the dosa, also it gets beautifully browned)
Mix the batter well and start pouring the batter (using a laddle or a small cup) from outside of tava to inside forming a circle, wait until bottom is nicely brown. This will take some time. Top will be automatically cooked, if required you can flip and cook the other side for few seconds. Use oil if its not a non-stick pan.
Wipe the tava with tissue, sprinkle onions on tava and proceed with next dosa. Maintain high heat for better results.
Give the batter a nice mix before making each dosa.
I saw an alternative method of making this dosa here and I had followed this method and the results were really good. Give the batter a good mix , try to take handful of batter WITH YOUR HAND and sprinkle on the hot tava. Repeat this 3-4 times trying to fill in the tava here and there with the batter and until u see a decent round shape on the tava. Let the bottom brown, flip and serve.
This method was really successful for me (Infact I did not use a bit of oil in my nonstick pan except for my first dosa) and the dosa came off pretty well maintaining its shape with much ease.