Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Peel and dice the sweet potato, carrots, and parsnips into uniform 1-inch pieces to ensure even cooking.
In a large bowl, toss the chopped root vegetables with 0.5 tbsp of olive oil, half the garlic, and a pinch of salt and pepper.
Spread the vegetables in a single layer on the prepared baking sheet and roast for 15 minutes.
While vegetables roast, rub the chicken breast with the remaining 0.25 tbsp of olive oil, garlic, rosemary, thyme, salt, and pepper.
Move the vegetables to the sides of the pan and place the chicken breast in the center.
Return the pan to the oven and roast for an additional 20-25 minutes, or until the chicken reaches an internal temperature of 165°F.
Let the chicken rest for 5 minutes before slicing to keep it juicy, then serve alongside the caramelized vegetables.