Begin by preparing the marinade in a large bowl. Combine soy sauce, banana ketchup, brown sugar, garlic, pineapple juice, oyster sauce, black pepper, and paprika. Mix well until the sugar dissolves and the marinade becomes smooth and slightly thick.

Add the pork cubes to the marinade and mix thoroughly to ensure every piece is fully coated. Cover and refrigerate for at least 4 hours, but overnight marination is best for deeper flavor and more tender meat.

Once marinated, thread the pork pieces onto skewers, packing them closely but not too tight so they cook evenly. If using wooden skewers, soak them in water for about 30 minutes beforehand to prevent burning.

Preheat your grill to medium heat. Place the skewers on the grill and cook slowly, turning frequently to prevent burning due to the sugar in the marinade. As the pork cooks, baste it with the oil and reserved marinade mixture to keep it juicy and help develop a sticky, caramelized glaze.

Continue grilling for about 15–20 minutes, turning regularly, until the pork is fully cooked, slightly charred on the edges, and glossy from the glaze. Make sure the internal temperature reaches at least 145°F (63°C), though slightly higher gives a more tender texture.

Remove from the grill and let the skewers rest for a few minutes. Garnish with chopped green onions or diced red onion for a fresh contrast.