Start by cutting the pork tenderloin and fresh pineapple into 1-inch cubes for even cooking. Next, chop the red onion and green bell pepper into similar-sized pieces.

In a medium bowl, whisk together BBQ sauce, olive oil, garlic powder, and black pepper until well combined.

Combine the pork cubes with the pineapple, chopped onion, and bell pepper in a large bowl. Pour the BBQ marinade over the mixture and toss well. Let it marinate for at least 10 minutes.

If using wooden skewers, soak them in water for at least 30 minutes. Begin threading the marinated pork and vegetables onto the skewers, alternating ingredients.

Preheat your grill to medium heat, around 350°F (175°C). Grill the skewers for about 15-20 minutes, turning frequently until the pork is cooked and veggies are tender.

In the final minutes of grilling, brush the skewers with additional BBQ sauce. Let them rest for a few minutes before serving.