Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Peel the carrot and slice it into half-inch rounds, and cut the red onion into thin wedges.
Mince the garlic cloves and whisk them in a small bowl with the rosemary, thyme, and half of the olive oil.
Pat the chicken breast dry with a paper towel and rub it thoroughly with the garlic-herb oil mixture.
Place the chicken on the prepared baking sheet and surround it with the broccoli florets, carrots, and onions.
Drizzle the remaining olive oil over the vegetables and season everything with sea salt and black pepper.
Toss the vegetables gently to coat and spread them out in a single layer to ensure even roasting.
Bake for 22 to 25 minutes until the chicken reaches an internal temperature of 165°F and the vegetables are golden.
Let the chicken rest for 5 minutes before slicing to ensure the meat stays juicy and tender.