always use a heavy bottom pan or well-seasoned cast-iron tawa to make rava dosa. iron skillet pan is the best to prepare dosas. seasoned tawa is the one which is used earlier to prepare dosa. grease the pan well and rub it with a slice of onion before pouring each dosa. also do not use the same tawa in which you prepare roti or chapati. maintain the tawa separately for both. in case if the dosa sticks to the non-stick tawa, pour a small amount of batter into it and prepare a small size dosa, after 2-3 dosas, the dosas won’t stick to the pan as the tawa would be hot.