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 uniform 1-inch chunks to ensure even cooking.
Mince the fresh garlic cloves and finely chop the rosemary and thyme leaves.
In a large mixing bowl, combine the chicken breast, chopped root vegetables, olive oil, minced garlic, herbs, sea salt, and black pepper.
Toss everything thoroughly until the chicken and vegetables are well-coated in the herb oil.
Spread the mixture in a single layer on the prepared baking sheet, ensuring space between pieces for proper browning.
Roast for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and golden.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy.
Serve the sliced chicken alongside the roasted root vegetables.