Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Peel the sweet potato if desired, then dice into 1/2-inch cubes. Chop the red bell pepper into 1-inch pieces.
Place the chicken breast, sweet potato cubes, broccoli florets, and bell peppers onto the baking sheet in a single layer.
Drizzle the olive oil over the chicken and vegetables.
In a small bowl, combine the rosemary, thyme, garlic powder, sea salt, and black pepper, then sprinkle the mixture evenly over everything.
Toss the vegetables with tongs to coat them in the oil and spices, and flip the chicken to ensure both sides are seasoned.
Roast for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the sweet potatoes are fork-tender and golden.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure it remains juicy.