To a large bowl add the jowar flour, onion, green chili, ginger, cumin seeds, curry leaves, cilantro and salt. Mix well to combine.
In a small bowl add the yogurt and a cup of water. Whisk it to remove any lumps.
Add the yogurt mixture to the jowar flour. Mix it well to remove any lumps. Cover and set a side for 20 minutes.
After 20 minutes, add ¾ th of water to the batter. Mix it well. The consistency of the batter should be very similar to butter milk. (If you are not sure about the amount of water, make one dosa and check. If the dosa is thicker, add some more water)
To make the dosa - heat a cast iron skillet, once the pan is hot drizzle some oil and wipe it off with a paper towel.
Take a ladle full of batter and pour the batter about 6 inches above the pan, this will give us a nice lacey dosa. Pour the batter from outside to inside and fill in any gaps, making sure not to pour the batter on the same spot again. Cook the dosa in medium-high flame.
Cook the dosa for one minute. Now drizzle some oil on the sides and in the holes in the middle.
Cook for another 1-2 minutes, time depends on the heat and the pan used. Once the dosa looks crispy on the sides, you can use a spatula to loosen it up. Gently remove the dosa and serve with your favorite chutney.
Repeat with the rest of the batter. Mix the batter every time before making the dosa.