Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Prepare the vegetables by peeling and chopping the carrots into 1-inch pieces, cubing the sweet potato, and slicing the red onion into thick wedges.
Place the chicken breast in the center of the baking sheet and surround it with the prepared carrots, sweet potatoes, and onions.
In a small glass bowl, whisk together the extra virgin olive oil, minced garlic, chopped rosemary, thyme, sea salt, and black pepper.
Drizzle the herb oil mixture evenly over the chicken and vegetables, using your hands or a spatula to toss the vegetables until they are well-coated.
Roast in the center of the oven for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the root vegetables are fork-tender and slightly browned.
Remove from the oven and let the chicken rest for 5 minutes before slicing against the grain to ensure maximum juiciness.