Boiled chewy sweet potato chunks ???

Has anyone tried something like this in Taiwan or Taiwanese restaurant? This is a bowl of chewy sweet potato chunks called 'dee kwa yuan ???' or 'fun shu yuan ???', a popular Taiwanese dessert. These chunks are similar to Cantonese glutinous rice balls 'tang yuan ??' but much chewier. The first time I made this dessert following a recipe I found on the internet, it was far too chewy for my taste