Soak four wooden skewers in water for at least 20 minutes to prevent burning on the grill.
Cut the pork tenderloin and pork belly into uniform 1-inch cubes for even cooking.
In a medium mixing bowl, whisk together the gochujang paste, coconut aminos, honey, toasted sesame oil, rice vinegar, minced garlic, and grated ginger.
Thread the pork cubes onto the skewers, alternating between the lean tenderloin and the richer pork belly pieces.
Brush the skewers generously with the gochujang marinade, ensuring all sides are well-coated.
Preheat a grill or grill pan to medium-high heat and lightly grease the surface.
Grill the skewers for 8 to 10 minutes, turning every 2 minutes and basting with any remaining sauce until the pork is cooked through and charred.
Remove from heat and garnish with toasted sesame seeds and thinly sliced green onions before serving.