Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Peel the carrots, parsnips, and sweet potato, then chop them into uniform 1-inch cubes to ensure even cooking.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a large mixing bowl, combine the cubed vegetables and the chicken breast.
Drizzle with extra virgin olive oil and add the minced garlic, rosemary, thyme, sea salt, and black pepper.
Toss everything thoroughly with your hands or tongs until the chicken and vegetables are well 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 in the center of the oven for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and slightly caramelized.
Remove from the oven and let the chicken rest for 5 minutes before slicing it into strips.
Plate the sliced chicken alongside the roasted root vegetables and serve immediately.