In a small bowl, whisk together the gochujang, coconut aminos, sesame oil, honey, minced ginger, and minced garlic to create the marinade.
Slice the pork tenderloin into 1-inch cubes and place them in a bowl, pouring half of the marinade over the meat to coat thoroughly.
Let the pork marinate in the refrigerator for at least 30 minutes to allow the flavors to penetrate.
Chop the red bell pepper and red onion into 1-inch pieces suitable for skewering.
Thread the marinated pork cubes onto skewers, alternating with pieces of bell pepper and red onion, then season with sea salt and black pepper.
Preheat a grill or cast-iron grill pan over medium-high heat and lightly coat with a small amount of oil.
Grill the skewers for 3-4 minutes per side, or until the pork is cooked through and the vegetables are slightly charred.
During the last 2 minutes of cooking, brush the remaining marinade over the skewers for a glossy finish.
Remove from heat and garnish with toasted sesame seeds and sliced green onions before serving.