Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Peel and chop the sweet potato, carrots, and parsnips into uniform 1-inch cubes to ensure even roasting.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a large bowl, toss the chopped vegetables with half of the olive oil, half of the minced garlic, and a pinch of the sea salt and black pepper.
Place the chicken breast on the baking sheet and rub with the remaining olive oil, garlic, rosemary, thyme, salt, and pepper.
Arrange the seasoned vegetables in a single layer around the chicken breast on the baking sheet.
Roast for 25-30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and golden brown.
Let the chicken rest for 5 minutes before slicing to keep it juicy, then serve alongside the roasted root vegetables.