In a mixing bowl, add rava / semolina, rice flour and maida (all-purpose flour). well.
Add chopped onions, grated ginger, finely chopped green chillies, 4-5 curry leaves roughly tared, 1 teaspoon of cumin seeds, a handful of coriander leaves, and salt to taste. Mix all ingredients.
Add 2 cups of water, cover with a lid and let the batter rest for 20-30 minutes
After resting, mix the batter well and add 2 cups of water. The consistency of the dosa batter should be free-flowing (very thin) hence add the water accordingly.
Heat tava / griddle, add a teaspoon of oil and spread it evenly over the skillet / tava.
Pour the batter using a ladle starting from the edges toward the centre.
Drizzle a little oil along the edges and let the rava dosa cook on medium flame.
Cook the dosa from both sides till they are golden and crispy.
Our crispy, thin, lacy plain Rava dosa is ready.
Serve hot with coconut chutney and sambar.
At this time, you can opt to spread a spoonful of potato masala all over the Rava and roll the dosa to serve. (I personally like to serve the potato masala by the side, that way the crispy rava dosa doesn't tend to get soggy).