Slice the pork tenderloin into thin 1/4-inch strips to mimic the texture of pork belly while staying lean.
In a small bowl, whisk together the gochujang, tamari, sesame oil, rice vinegar, garlic powder, and ginger powder until smooth.
Toss the pork strips in a bowl with half of the prepared gochujang sauce and let marinate for at least 10 minutes.
Heat the avocado oil in a large cast-iron skillet over medium-high heat until it begins to shimmer.
Add the pork to the skillet in a single layer and sear for 3 minutes per side until the edges are dark and caramelized.
Warm the corn tortillas in a dry pan over medium heat for 30 seconds on each side until soft and pliable.
Shred the red cabbage into thin ribbons and finely slice the scallions for the topping.
Fill each tortilla with the seared pork, then top with shredded cabbage, a drizzle of the remaining sauce, scallions, and sesame seeds.