Heat a dosa tawa. When the tawa is hot, pour 1-2 ladles of the kambu dosai batter and spread in concentric circles with the back of the ladle to make a thin dosai. Drizzle oil around the edges of the dosai. Cover with a lid and cook for a minute or until the underside is golden brown. Use a spatula to lift the dosai from the tawa. Serve hot with chutney of your choice. Enjoy!