Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Peel the sweet potato and carrots, then dice them into uniform 1-inch cubes to ensure even cooking.
In a small bowl, whisk together the olive oil, minced garlic, dried rosemary, dried thyme, sea salt, and black pepper.
Place the chicken breast on one side of the baking sheet and the diced vegetables on the other side.
Drizzle the garlic-herb oil over the chicken and vegetables, tossing the vegetables and brushing the chicken to coat thoroughly.
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 vegetables are tender and golden.
Let the chicken rest for 5 minutes before slicing to keep it juicy, then serve alongside the roasted root vegetables.