What is the best material for a tawa?

What is the optimal material to craft a tawa, the traditional Indian flat griddle used for cooking a variety of dishes? Is it the durability and heat retention of cast iron that makes it the top choice, or does stainless steel offer a more modern and hygienic alternative? Could aluminum be a lightweight and efficient option, despite concerns about potential health risks? Alternatively, are there any innovative materials emerging in the market that could revolutionize tawa making, offering benefits such as improved heat distribution and ease of maintenance? Ultimately, what criteria should one consider when selecting the best material for a tawa?