Soak four wooden skewers in water for at least 20 minutes to prevent burning.
In a small bowl, whisk together the gochujang, tamari, sesame oil, rice vinegar, honey, minced garlic, and grated ginger until smooth.
Cut the pork tenderloin, pork belly, and red bell pepper into uniform 1-inch cubes.
Season the pork and peppers lightly with sea salt and black pepper.
Thread the ingredients onto the skewers, alternating between the lean pork tenderloin, the rich pork belly, and the bell pepper chunks.
Preheat a grill or grill pan over medium-high heat and lightly grease the surface.
Place the skewers on the grill and cook for 3-4 minutes per side, brushing generously with the gochujang glaze during the last few minutes of cooking.
Ensure the pork is cooked through and the glaze is caramelized and slightly charred before removing from heat.
Serve immediately while hot and glistening.