Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Peel the carrots and parsnips, then slice them into 1/2-inch thick rounds or diagonal coins to ensure even roasting.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a large mixing bowl, toss the sliced carrots and parsnips with half of the olive oil, half of the minced garlic, and a pinch of salt and pepper.
Place the chicken breast on the prepared baking sheet and rub with the remaining olive oil, garlic, rosemary, thyme, salt, and pepper.
Arrange the seasoned root vegetables in a single layer around the chicken on the baking sheet.
Roast in the oven for 20 to 25 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 to keep it juicy.
Serve the sliced chicken alongside the roasted root vegetables and enjoy immediately.