In one sentence, describe what the following article is about:

If you have refrigerated your batter, you will need to remove it from the fridge and allow it to sit at room temperature for at least an hour.  The dosas work better with room-temperature batter. Bring the cooking surface up to temperature for about 10 minutes with medium heat. An appropriate cooking surface would be a nonstick skillet, an iron griddle, or a flat tawa. The best way to prepare and season the cooking surface for making dosas is to pour a few drops of oil on a cut onion and rub the onion with pressure around the pan.  You may find that you need to adjust the amount of oil depending on the cooking surface that you use, but one or two drops should be enough. The size of your dosas will be, in part, determined by the limitations of your cooking surface.  Dosas can be made small, for individuals, or larger, to share.  If you plan to make larger, shareable dosas, you will need to double the amount of batter you use for each one.
Bring the batter to room temperature. Heat the cooking surface. Season the cooking surface. Decide what size you want to make your dosas.