Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Peel the sweet potato and dice into 1-inch cubes; peel the carrots and slice 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, sweet potato cubes, and carrot rounds.
Drizzle with olive oil and sprinkle with 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 the pieces are not overlapping.
Roast for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are fork-tender and golden brown.
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.