Cut the pork tenderloin into 1-inch cubes and set aside in a medium mixing bowl.
In a small bowl, whisk together the gochujang, tamari, honey, sesame oil, grated ginger, and minced garlic until smooth.
Pour the marinade over the pork cubes, tossing well to ensure every piece is coated, and let marinate for at least 15 minutes.
While the pork marinates, cut the red bell pepper into 1-inch squares and slice the green onions into 1-inch batons.
Thread the marinated pork, bell peppers, and green onions onto skewers, alternating between the meat and vegetables.
Preheat a grill or broiler to medium-high heat and lightly grease the grate or a foil-lined pan.
Cook the skewers for 3 to 4 minutes per side, or until the pork is cooked through and the edges are beautifully charred.
Remove from heat and sprinkle with sesame seeds before serving immediately.