Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Peel the carrots and parsnips, then slice them into 1-inch thick rounds or bite-sized chunks.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a large mixing bowl, combine the chicken breast, carrots, and parsnips.
Drizzle with olive oil and sprinkle with the minced garlic, chopped herbs, sea salt, and black pepper.
Toss everything thoroughly to ensure the chicken and vegetables are evenly coated in the oil and seasonings.
Spread the mixture in a single layer on the prepared baking sheet, ensuring the chicken is not crowded by the vegetables.
Roast for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the root vegetables are tender and lightly browned.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy.