Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Pat the chicken breast completely dry with paper towels to ensure the skin or surface gets a nice golden crisp.
Trim the ends off the Brussels sprouts and halve them; peel and slice the carrots into half-inch rounds.
In a large mixing bowl, toss the Brussels sprouts and carrots with half of the olive oil, half of the salt, and half of the pepper.
In a small ramekin, whisk together the remaining olive oil, lemon juice, minced garlic, rosemary, and thyme.
Arrange the vegetables on the baking sheet, leaving space in the center for the chicken breast.
Place the chicken on the sheet and brush the lemon-herb mixture generously over the top and sides.
Roast for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and caramelized.
Remove from the oven and let the chicken rest for 5 minutes before slicing to lock in the juices.