This is a simple and easy instant dosa recipe from aayisrecipes.com which I have tried several times.
1 cup rice flour
2 tbsp rava (sooji)
1/2 tsp jeera
1 tsp chilli powder
1 medium onion, finely chopped
In a large bowl, mix rice flour, rava, jeera, chilli powder and finely chopped onion. Add salt [I added approx 1 1/4 tsp].
Add enough water [I added approx 2 cups] and mix thoroughly to get a thin dosa batter.
Heat a flat non-stick pan. Sprinkle oil and spread it across with a spatula.
When the oil is sufficiently hot [you can check by adding just one drop of water - if it sizzles, oil is hot enough], pour a ladleful of batter onto the tawa and let it spread across. You can lift the tawa and move it around so that it spreads more.
Cover and cook for a few minutes. Uncover and carefully flip the dosa. Cook for another few minutes.
We like this crispy dosa best with loshne (garlic) chutney, but if you don't have time to make that, you can have it with tomato ketchup (mixed with some hot chilli sauce).