Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Peel the sweet potato and cut into 1-inch cubes, and slice the carrots into half-inch thick rounds.
Mince the garlic cloves finely.
In a large mixing bowl, combine the chicken breast, sweet potato cubes, and carrot rounds.
Drizzle with olive oil and add the minced garlic, rosemary, thyme, sea salt, and black pepper.
Toss everything thoroughly until the chicken and vegetables are evenly coated in the oil and herbs.
Spread the mixture in a single layer on the prepared baking sheet, ensuring pieces aren't overcrowded so they roast rather than steam.
Roast for 25 to 30 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 and serving with the roasted root vegetables.