Preheat oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Peel and chop the carrots, parsnips, and sweet potato into uniform 1-inch pieces to ensure even cooking.
Place the chicken breast and chopped vegetables in a large mixing bowl.
Add the olive oil, minced garlic, rosemary, thyme, 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 is not crowded by the vegetables.
Roast for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender.
Let the chicken rest for 5 minutes before slicing to keep it juicy.