Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Peel the carrots and parsnips, then chop them into 1-inch bite-sized pieces. Slice the red onion into thick wedges.
In a large mixing bowl, combine the chopped vegetables and the chicken breast.
Drizzle with extra virgin olive oil and add the minced garlic, dried rosemary, dried thyme, sea salt, and black pepper.
Toss everything thoroughly to ensure the chicken and vegetables are evenly coated in the oil and seasonings.
Spread the mixture onto the prepared baking sheet in a single layer, ensuring the chicken is not crowded by the vegetables.
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 lightly browned.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure it remains juicy.
Plate the sliced chicken alongside the roasted root vegetables and serve immediately.