Soak wooden skewers in water for 20 minutes to prevent burning during grilling.
In a small bowl, whisk together the gochujang, tamari, sesame oil, maple syrup, ginger, and garlic until smooth.
Cut the pork tenderloin into 1-inch cubes and toss them with half of the prepared gochujang marinade.
Slice the zucchini into rounds and the red bell pepper into 1-inch squares, then season lightly with sea salt and black pepper.
Thread the marinated pork and vegetables alternately onto the soaked skewers.
Preheat a grill pan or outdoor grill to medium-high heat and lightly coat the surface with a high-heat oil.
Grill the skewers for 3 to 4 minutes per side until the pork is cooked through and the vegetables are beautifully charred.
Brush the remaining gochujang glaze over the skewers during the final minute of cooking for a glossy finish.
Remove from heat and garnish with sesame seeds and sliced green onions before serving warm.