While a roti tawa and a dosa tawa may appear similar, they differ in the ways of cooking and the required ingredients. Dosa batter is more liquid and flows freely on the cookware surface. If the tawa is concave, the batter concentrates in the center and makes the dosa thick in the middle and thin around the edges. For this reason, you should always choose a flat tawa for making dosa. On the other hand, roti, paratha, or chapati dough is more solid, and you can make them on both flat and concave tawas. Also, a dosa tawa must be non-stick, which is not essential for a roti tawa. So, choose a concave non-stick tawa if you are not planning to prepare dosa. A flat non-stick tawa is suitable for both roti and dosa. If you cook only roti, you can select a traditional iron tawa without a non-stick coating.