Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Peel the carrots and parsnips, then chop them into uniform 1-inch chunks to ensure even roasting.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a large mixing bowl, toss the chopped root vegetables with half of the olive oil, half of the minced garlic, and half of the fresh herbs.
Pat the chicken breast dry with a paper towel, then rub both sides with the remaining olive oil, garlic, herbs, sea salt, and black pepper.
Spread the seasoned vegetables onto the prepared baking sheet and place the chicken breast in the center, ensuring nothing is overcrowded.
Roast in the oven for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are fork-tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep the juices intact.