If I didn't know better, at first glance, these things remind me of some kind of tubular deep sea creature that makes it's home around thermal vents at the bottom of the Mariana Trench. In fact, they are made from tofu, more precisely, the skim from soy milk. Bean skins (or tofu skins) are chewy and delicious.
When I lived in New York City's Chinatown, I was in an apartment above the world's best (cheap) Cantonese buffet. There were many exotic delicacies. You were allowed 3 choices from the buffet with a bowl of rice for $2.50. Though, at that time, I was a full on carnivore, I loved it when they brought out the steaming stainless steel pan of fresh bean skins with veggies and brown sauce.
In many towns with a decent population, there will more than likely be an Asian market tucked away in a back alley or in a strip mall with all the fixings for a fantastic meal.