Prepare the marinade by whisking the gochujang, tamari, sesame oil, honey, grated ginger, and minced garlic in a small bowl until smooth.
Slice the pork tenderloin into 1-inch cubes and place them in a glass bowl, tossing with half of the prepared gochujang marinade.
Allow the pork to marinate for at least 15 minutes at room temperature to absorb the bold flavors.
Slice the zucchini into thick half-moons and lightly season with sea salt and black pepper.
Thread the marinated pork cubes and zucchini pieces onto skewers, alternating them for even cooking.
Heat a grill pan or outdoor grill over medium-high heat and lightly grease with a touch of oil if needed.
Grill the skewers for 3 to 4 minutes per side, brushing with the remaining marinade during the final 2 minutes of cooking for a glossy finish.
Remove from heat once the pork is cooked through and the edges are slightly charred and caramelized.
Garnish the skewers with toasted sesame seeds and thinly sliced green onions before serving.