Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Peel and cube the sweet potato into 1-inch pieces, then toss them on the baking sheet with 0.5 tbsp of olive oil, a pinch of sea salt, and black pepper.
Roast the sweet potatoes for 20-25 minutes, flipping halfway through, until the edges are golden and crispy.
While the potatoes roast, season the chicken breast with garlic powder, smoked paprika, remaining sea salt, and black pepper.
Heat the remaining 0.5 tbsp of olive oil in an oven-safe skillet over medium-high heat and sear the chicken for 3-4 minutes per side.
Brush the chicken generously with the sugar-free BBQ sauce and transfer the skillet to the oven for the last 8-10 minutes of the potato roasting time, or until the internal temperature reaches 165°F.
Steam the broccoli florets for 5 minutes until tender-crisp and vibrant green.
Slice the chicken and serve alongside the roasted sweet potatoes and steamed broccoli.