Cut the pork tenderloin and pork belly into uniform 1-inch cubes for even cooking.
In a medium bowl, whisk together the gochujang, tamari, toasted sesame oil, rice vinegar, grated ginger, minced garlic, and honey until smooth.
Add the pork cubes to the bowl and toss thoroughly to ensure every piece is coated in the spicy marinade, then let it sit for 10 minutes.
Thread the marinated pork onto skewers, alternating between the lean tenderloin and the flavorful pork belly pieces.
Preheat a grill or cast-iron grill pan over medium-high heat and lightly oil the surface to prevent sticking.
Grill the skewers for 3-4 minutes per side until the pork is cooked through and develops a beautiful charred crust.
Season the sliced cucumbers with sea salt and black pepper, then serve the skewers alongside the cucumber and kimchi.
Garnish the dish with toasted sesame seeds and thinly sliced green onions for a fresh crunch before serving.