Answer: This is a specialty dish called pork balls.
The way to make this dish is similar to sausage, except that the outer shell is the pig's bladder, or the bladder of the pig.
After cutting the lean meat and fat into small pieces, mixing with traditional Sichuan spices (mainly the salty and spicy flavors of salt, chili, garlic, pepper), people will stuff the meat into the pre-cleaned pig bladders.
The pig bladder is very tough so it can hold a lot of meat. Once stuffed, tie the mouth tightly, tie the pig bladder tightly with string, then hang it up, smoke and dry in a windy place or in the kitchen.