Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Pat the chicken breast completely dry with a paper towel to ensure the skin gets a beautiful golden-brown sear.
Slice the carrots into rounds, dice the parsnips into bite-sized cubes, and halve the Brussels sprouts.
In a large mixing bowl, toss the prepared vegetables with half of the olive oil and a small pinch of sea salt and black pepper.
Spread the vegetables in a single layer across the baking sheet, leaving a space in the center for the chicken.
In a small bowl, combine the remaining olive oil with minced garlic, chopped rosemary, and thyme to create a herb rub.
Coat the chicken breast evenly with the herb rub and place it in the center of the baking sheet.
Roast for 20 to 25 minutes 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 ensure every bite is succulent and juicy.