Cut the pork loin and pork belly into uniform 1-inch cubes.
In a small mixing bowl, whisk together the gochujang, tamari, honey, sesame oil, minced garlic, and grated ginger to create the marinade.
Place the pork cubes in a glass bowl, pour the marinade over them, and toss until every piece is well-coated. Let it marinate in the refrigerator for at least 20 minutes.
Thread the pork onto skewers, alternating between the lean pork loin and the rich pork belly pieces.
Preheat a grill or grill pan over medium-high heat. Grill the skewers for 3-4 minutes per side, or until the pork is cooked through and the edges are beautifully caramelized and smoky.
While the pork grills, thinly slice the cucumber and toss it in a bowl with the rice vinegar, red pepper flakes, sea salt, and black pepper.
Serve the hot skewers immediately alongside the chilled cucumber salad for a balanced, clean meal.