Every South Indian family will have their own version of making Idli Podi. Some add just dhals, some add nuts to it, some add garlic, and some call it ellu podi by adding lot of sesame seeds. Some call it idli gun powder and I am not sure about the origin of this name.
Mom's version is with garlic and I usually make it that way. This time I tried without garlic . I also added sesame seeds and channa dhal. It came out pretty good.
Mix it along with ghee or sesame oil. Makes a great combination for idlis and dosas.