Slice the pork tenderloin into very thin strips to mimic the texture of traditional belly and season with sea salt and black pepper.
In a small bowl, whisk together the tamari, honey, and rice vinegar to create a savory glaze.
Heat the sesame oil in a large skillet over medium-high heat and sear the pork strips until golden brown and fully cooked.
Pour the tamari mixture into the skillet and toss with the pork for 1 minute until the sauce reduces into a thick, glossy glaze.
Steam the bao buns in a steamer basket over boiling water for 3 to 5 minutes until they are soft and pillowy.
Thinly slice the cucumber and julienne the carrots into matchsticks, then toss them with a tiny splash of rice vinegar.
Assemble the buns by filling each with the glazed pork, pickled vegetables, fresh scallions, and a drizzle of sriracha.