Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Peel and chop the carrots, parsnips, and red onion into uniform 1-inch chunks to ensure even cooking.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a large mixing bowl, whisk together the extra virgin olive oil, minced garlic, rosemary, thyme, sea salt, and black pepper.
Add the chicken breast and chopped root vegetables to the bowl, tossing thoroughly until every piece is well-coated in the herb oil.
Spread the mixture in a single layer on the prepared baking sheet, making sure the chicken is not covered by the vegetables.
Roast for 22-25 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 with the roasted vegetables.