Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Peel the carrots and parsnips, then cut them into 1-inch thick chunks; slice the red onion into thick wedges.
In a large mixing bowl, combine the chicken breast, carrots, parsnips, and onion.
Drizzle with extra virgin olive oil and add the minced garlic, chopped rosemary, thyme, sea salt, and black pepper.
Toss everything thoroughly until the chicken and vegetables are evenly coated in the oil and herbs.
Spread the mixture onto the prepared baking sheet in a single layer, ensuring the chicken is not covered by the vegetables.
Roast for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are fork-tender and caramelized.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure maximum juiciness.