Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Peel the carrots and parsnips, then chop them into uniform 1-inch pieces to ensure even cooking.
Place the chicken breast and the chopped root vegetables onto the prepared baking sheet.
Mince the garlic and finely chop the fresh rosemary and thyme leaves.
Drizzle the olive oil over the chicken and vegetables, then sprinkle with the sea salt, black pepper, minced garlic, and fresh herbs.
Toss the vegetables and rub the chicken thoroughly to ensure everything is well-coated in the oil and seasoning.
Spread the ingredients out in a single layer, ensuring the chicken is not covered by the vegetables.
Roast in the center of the oven for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and slightly caramelized.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy.