Prepare the pork: Slice the pork belly into uniform 1-inch cubes to ensure even cooking and maximum surface area for the glaze.
Create the marinade: In a medium glass bowl, whisk together the gochujang, tamari, honey, toasted sesame oil, minced garlic, grated ginger, and rice vinegar until smooth.
Marinate the meat: Add the pork cubes to the bowl, tossing thoroughly to coat every side, and let it marinate for at least 15 minutes to infuse the bold flavors.
Assemble the skewers: Thread the marinated pork cubes onto skewers, leaving a tiny bit of space between each piece to allow the heat to properly crisp the edges.
Grill to perfection: Place skewers on a hot grill or in a 400°F air fryer for 12-15 minutes, turning halfway through, until the pork is tender and the glaze is beautifully charred.
Final touch: Transfer the skewers to a serving plate and garnish with thinly sliced green onions and a sprinkle of toasted sesame seeds before serving.