dosa tawa can be seasoned in the following ways: rub the tawa with gingelly oil and soak it in washed rice water for a week. rub the tawa with half onion before spreading the dosas. heat the tawa, sprinkle salt, switch off the flame, wipe with cloth and grease oil after it cools. clean the tawa with hot water and rub it with oil. keep in the oven for one-hour upside down. also do not wash the tawa when it is too hot and do not put cold liquids on the cast iron tawa. avoid hard soaps, detergents, and steel scrubbers.