Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Peel the carrots and parsnips, then slice them into 1-inch thick rounds to ensure even cooking.
In a medium mixing bowl, toss the sliced carrots and parsnips with 0.5 tablespoon of olive oil, half of the minced garlic, and half of the rosemary, thyme, salt, and pepper.
Spread the seasoned vegetables in a single layer on one side of the prepared baking sheet.
Pat the chicken breast dry with a paper towel and rub both sides with the remaining 0.5 tablespoon of olive oil, garlic, and the rest of the herb seasoning.
Place the chicken breast on the other side of the baking sheet next to the vegetables.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and golden.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy, then serve alongside the roasted root vegetables.