Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Peel and chop the sweet potato, carrots, and parsnips into uniform 1-inch chunks to ensure even roasting.
Finely mince the garlic cloves.
In a large mixing bowl, toss the chopped root vegetables with 0.5 tbsp of olive oil, half of the minced garlic, and half of the sea salt and black pepper.
Rub the chicken breast thoroughly with the remaining 0.5 tbsp of olive oil, the rest of the garlic, dried rosemary, dried thyme, and the remaining salt and pepper.
Spread the seasoned root vegetables in a single layer on the prepared baking sheet and roast for 10 minutes.
Carefully move the vegetables to the sides of the pan, place the chicken breast in the center, and roast for an additional 20-25 minutes until the chicken reaches an internal temperature of 165°F.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep the meat juicy and tender.