Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Wash and dice the red potato into half-inch cubes and slice the carrots into thin half-moons.
Cut the broccoli into bite-sized florets and thinly slice the red onion.
Mince the fresh garlic cloves finely.
In a large mixing bowl, toss the potato cubes, sliced carrots, broccoli florets, and red onion with half of the olive oil, half of the sea salt, and half of the black pepper.
Place the chicken breast on one side of the prepared sheet pan and rub it with the remaining olive oil.
Season the chicken breast evenly on both sides with the dried rosemary, dried thyme, garlic powder, minced fresh garlic, and the remaining sea salt and black pepper.
Spread the seasoned vegetables in a single layer on the other side of the sheet pan, ensuring they are not overcrowded.
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 lightly browned.
Remove from the oven and let the chicken rest for 5 minutes before slicing it against the grain and serving alongside the roasted vegetables.