Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Peel and chop the carrots and parsnips into 1-inch pieces, and roughly chop the red onion.
In a small bowl, whisk together the extra virgin olive oil, minced garlic, chopped rosemary, thyme, sea salt, and black pepper.
Place the chicken breast and chopped vegetables in a large mixing bowl and pour the herb oil over them, tossing thoroughly to ensure everything is evenly coated.
Spread the vegetables in a single layer on the prepared baking sheet and nestle the chicken breast in the center.
Roast in the oven for 25 to 30 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 the meat juicy.
Serve the sliced chicken alongside the roasted root vegetables, drizzling any remaining pan juices over the top.