Bao Du is a study in texture. Fresh lamb or beef tripe is sliced into strips and flash-boiled in water for mere seconds — just long enough to cook through while retaining an incredible crunch. It's served immediately with a dipping sauce of sesame paste, fermented tofu, chives, and sesame oil. The key is perfect timing: undercooked and it's rubbery; overcooked and it's tough. When done right, the tripe has a satisfying snap.
Bao Du originated during the Qing Dynasty as a street food in Beijing's markets. It's one of the few remaining dishes that requires the skill of a specialist bao du chef.