1. Preheat your oven to 400 F (200 C). Line a large baking sheet with parchment paper or aluminum foil for easier cleanup.

2. Wash and prepare your vegetables. Quarter the small red potatoes, core and cut the bell pepper into 1-inch pieces, and cut the red onion into 1-inch wedges. Aim for roughly uniform sizes so they cook evenly.

3. In a large bowl, combine the cut chicken pieces, potatoes, bell pepper, and red onion. Drizzle with olive oil, then sprinkle with garlic powder, smoked paprika, salt, and black pepper. Toss everything together thoroughly until the chicken and vegetables are evenly coated in the seasonings.

4. Spread the seasoned chicken and vegetables in a single layer on the prepared baking sheet. Ensure there’s a little space between the pieces to allow for even roasting and browning. Overcrowding the pan can lead to steaming instead of roasting.

5. Place the sheet pan in the preheated oven and bake for 15 minutes. This initial bake allows the vegetables to start softening and the chicken to begin cooking through before the BBQ sauce is added.

6. Carefully remove the sheet pan from the oven. Drizzle the 1/2 cup of BBQ sauce over the chicken and vegetables. Toss gently on the pan to coat everything evenly. Return the pan to the oven and bake for another 10-15 minutes, or until the chicken is cooked through (internal temperature reaches 165 F / 74 C) and the vegetables are tender and slightly caramelized. The sauce should be bubbly and slightly thickened.

7. Once cooked, remove the sheet pan from the oven. Let the dinner rest for 5 minutes before serving. This allows the juices in the chicken to redistribute, ensuring it stays moist. Garnish with fresh chopped parsley, if desired, and serve with extra BBQ sauce on the side.