Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Chop the broccoli into bite-sized florets, slice the bell pepper into thin strips, and cut the red onion into small wedges.
Place the chicken breast and all the prepared vegetables onto the baking sheet in a single layer.
Drizzle the olive oil over the chicken and vegetables, then sprinkle evenly with the dried oregano, thyme, garlic powder, sea salt, and black pepper.
Toss the vegetables to coat them thoroughly and rub the seasoning into both sides of the chicken breast.
Bake for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender with slightly browned edges.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure it stays juicy.