Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Prepare the vegetables by peeling and dicing the sweet potato into 1-inch cubes and slicing the carrots into 1/2-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 chicken and vegetables, then 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 herb mixture.
Spread the mixture in a single layer on the prepared sheet pan, ensuring the chicken pieces have space around them to roast properly.
Roast in the center of the oven for 25-30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and caramelized.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy.
Plate the sliced chicken alongside the roasted root vegetables and serve immediately.