Preheat your oven to 400°F and line a large sheet pan with parchment paper.
Prepare the vegetables by peeling and chopping the carrots and parsnips into 1-inch chunks, and halving the Brussels sprouts.
Mince the garlic and finely chop the fresh rosemary and thyme.
In a large mixing bowl, combine the chicken breast, carrots, parsnips, and Brussels sprouts.
Drizzle with extra virgin olive oil and add the minced garlic, rosemary, thyme, sea salt, and black pepper.
Toss everything thoroughly until the chicken and vegetables are evenly coated with the oil and herbs.
Spread the mixture in a single layer on the prepared sheet pan, ensuring the chicken has enough space to roast evenly.
Roast in the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the root vegetables are tender and golden.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure it remains juicy.