Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Peel and cube the sweet potato, carrots, and parsnips into uniform half-inch pieces.
In a large bowl, toss the root vegetables with half of the olive oil, half of the sea salt, and half of the black pepper.
Spread the vegetables in a single layer on one side of the prepared baking sheet.
In a small bowl, combine the remaining olive oil, minced garlic, chopped rosemary, and chopped thyme.
Rub the garlic-herb mixture over the chicken breast and season with the remaining salt and pepper.
Place the chicken breast on the other side of the baking sheet.
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.
Let the chicken rest for 5 minutes before slicing and serving alongside the roasted vegetables.