Cast iron retains heat more than any other material - this means that when you pour the dosa batter, it doesn’t cool down and enables a perfectly crisp dosa to form. Cast iron is a healthier choice! Teflon coatings of non-stick pans start leaching into your food after some time. From a well-seasoned cast iron pan, very little iron leaches into your cooking and if it does, it just adds to your dietary iron requirement. Its production is environment friendly. Well-seasoned cast iron behaves just like non-stick pans. It’s the closest to the large commercial iron griddles on which dosas are made commercially.