If using wooden skewers, soak them in water for at least 20 minutes to prevent burning.
Cut the pork tenderloin into 1-inch cubes and place them in a medium mixing bowl.
In a small bowl, whisk together the gochujang, tamari, honey, sesame oil, minced garlic, and grated ginger to create the marinade.
Pour two-thirds of the marinade over the pork, tossing to coat thoroughly, and let it marinate for 15 minutes.
Cut the zucchini into thick half-moons and the red bell pepper into 1-inch squares.
Thread the marinated pork, zucchini, and bell peppers onto the skewers, alternating between meat and vegetables.
Preheat a grill pan or outdoor grill over medium-high heat and lightly grease with a touch of oil.
Grill the skewers for 3-4 minutes per side, or until the pork is cooked through and the vegetables are slightly charred.
Brush the remaining marinade over the skewers during the last minute of cooking for a glossy finish.
Remove from heat and garnish with sliced green onions and toasted sesame seeds before serving.