Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Prepare the vegetables by peeling and dicing the sweet potato into 1/2-inch cubes and slicing the carrots into 1/4-inch thick rounds.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a large mixing bowl, combine the chicken breast, diced sweet potatoes, and sliced carrots.
Drizzle the olive oil over the mixture 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 seasonings.
Spread the mixture in a single layer on the prepared baking sheet, ensuring the chicken pieces are not covered by the vegetables.
Roast for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are fork-tender and slightly browned.
Remove from the oven and let the chicken rest for 5 minutes before slicing and serving with the roasted root vegetables.