Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Peel the sweet potato and carrots, then chop them into uniform 1-inch cubes to ensure they roast evenly.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a large mixing bowl, toss the chopped sweet potatoes and carrots with half of the olive oil, half of the minced herbs, salt, and pepper.
Rub the chicken breast with the remaining olive oil, garlic, and herbs, making sure the seasoning is distributed on all sides.
Spread the vegetables in a single layer on the baking sheet and place the chicken breast in the center.
Roast for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and golden brown.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy, then serve alongside the roasted vegetables.