Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Slice the carrots into thin rounds and cut the red onion into 1-inch wedges to ensure even roasting.
In a small bowl, whisk together the extra virgin olive oil, minced garlic, dried rosemary, dried thyme, sea salt, and black pepper.
Place the chicken breast, broccoli florets, carrots, and red onion onto the prepared sheet pan.
Drizzle the garlic-herb oil mixture over the chicken and vegetables, using your hands or a pastry brush to coat everything thoroughly.
Arrange the ingredients in a single layer, ensuring the chicken is not covered by vegetables so it browns properly.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and slightly browned.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy.