Grind/blend together the drained moong dal, salt, onion and green chili with just couple of teaspoons of water. Pulse it a couple of times. The mixture should not be very smooth but bit coarse.
Transfer this mixture into a mixing bowl and stir in the rice flour. Add few more teaspoons of water (if required) to make a batter of dropping consistency.
Heat a non stick pan and grease it with some ghee. Add a small ladle of the batter at the centre of the pan and smear it gently but quickly, moving your hand in concentric circles, to make a dosa. Being gentle and swift is very important.
Drizzle some coconut oil all over the dosa and allow it to cook till it turns golden brown underneath. Then gently flip it over and let it cook few more minutes. You will see golden spots appearing which means it is cooked.
Roll it over or fold it over to make a half moon and serve immediately with fresh coconut chutney of your choice.