Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Pat the chicken breast dry with a paper towel to ensure the skin or surface gets a beautiful golden sear during roasting.
Peel and slice the carrots and parsnips into 1-inch pieces, and cut the red onion into small wedges.
In a large mixing bowl, toss the carrots, parsnips, and onions with half of the olive oil, half of the sea salt, and half of the black pepper.
In a small ramekin, combine the remaining olive oil with minced garlic, chopped rosemary, and thyme to create a herb paste.
Rub the herb paste evenly over all sides of the chicken breast and season with the remaining salt and pepper.
Spread the vegetables in a single layer on the sheet pan and nestle the chicken breast in the center.
Roast for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and lightly browned.
Remove from the oven and let the chicken rest for 5 minutes before slicing to allow the juices to redistribute.