Heat a griddle, use a cast iron skillet for best results. Spread some oil and wipe it off. Sprinkle some water, if the water bubbles up and absorbs all the water, the pan is ready. Wipe off the excess water.
Take a ladle full of batter, pour the batter in the center of the griddle and using the back of the same ladle spread the batter in to a thin circle, making sure the edges are not very thick
Drizzle some oil on the sides and in the middle and cook for 30 seconds. Now add the onion mixture on one side, drizzle little oil on the onion mixture and press gently so that the onion mixture sticks to the dosa. Close the lid and cook for 30 seconds. The steam will help onions to get soft, you don’t want the taste of raw onion.
When you open the lid, you will see the sides and the center getting brown. Cook for another 45 seconds depending on how crispy you like the dosa. We are only going to cook the dosa on one side.
Scrape the sides of the dosa and roll it. Remove the dosa and enjoy with ginger chutney.