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 dice them into uniform 1-inch cubes to ensure even roasting.
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 carrots.
Drizzle with olive oil and sprinkle with the minced garlic, chopped herbs, sea salt, and black pepper, tossing thoroughly to coat every piece.
Spread the mixture in a single layer on the prepared baking sheet, ensuring the chicken and vegetables are not overcrowded.
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 immediately.