Cut the pork tenderloin and pork belly into uniform 1-inch cubes.
In a small mixing bowl, whisk together the gochujang, tamari, toasted sesame oil, rice vinegar, raw honey, minced garlic, and grated ginger.
Place the pork cubes in a glass bowl, pour the marinade over them, and toss to coat thoroughly; let marinate for at least 15 minutes.
Slice the zucchini into thick half-moons and the red bell pepper into 1-inch squares.
Thread the marinated pork and vegetables onto skewers, alternating between the different proteins and produce.
Lightly season the assembled skewers with sea salt and black pepper.
Preheat a grill pan or outdoor grill to medium-high heat and lightly coat with a high-smoke point oil.
Grill the skewers for 3-4 minutes per side, rotating until the pork is cooked through and the glaze is beautifully caramelized.