Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Peel and dice the sweet potato and carrots into uniform 1-inch cubes to ensure even cooking.
In a large mixing bowl, whisk together the olive oil, minced garlic, rosemary, thyme, sea salt, and black pepper.
Add the chicken breast and chopped root vegetables to the bowl, tossing thoroughly until every piece is coated in the herb oil.
Spread the chicken and vegetables in a single layer on the prepared baking sheet, ensuring they are not overcrowded.
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.
Let the chicken rest for 5 minutes before slicing to keep it juicy, then serve alongside the roasted vegetables.