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 roasting.
In a large mixing bowl, toss the chopped root vegetables with 0.5 tablespoon of olive oil, half of the rosemary, thyme, salt, and pepper.
Place the chicken breast on the prepared baking sheet and rub with the remaining 0.5 tablespoon of olive oil, garlic powder, and the rest of the herbs and seasoning.
Arrange the seasoned vegetables in a single layer around the chicken on the baking sheet, ensuring they aren't overcrowded.
Roast for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and golden brown.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy, then serve alongside the roasted vegetables.