Wash and soak the rice for 2 hours.
In a grinding jar add chopped cucumber, green chilies, grated coconut, turmeric powder, salt and water. You can grind the whole quantity in 2 or 3 batches so that it is easy to grind to a smooth batter. The batter should be so smooth that you should not be able to feel any rice grains. I used about 2 1/2 or slightly more water altogether. The batter should be of thin consistency as compared to normal idli or dosa batter. The batter does not need any fermentation.
Heat a large non-stick pan and lightly grease with oil using a kitchen tissue. Pour a ladle full of batter (1/4 cup) on to the pan and swirl the pan around so that the batter gets evenly spread to make thin crepes.
Cook the crepe for 2 minutes on medium heat or till the edges start to leave the sides.
Remove from pan and cool slightly before serving as these dosas stick to each other when hot.
Serve warm with coconut red chutney.