Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Peel and slice the carrots and parsnips into 1-inch chunks, and halve the Brussels sprouts.
In a large mixing bowl, combine the vegetables with the olive oil, minced garlic, rosemary, thyme, sea salt, and black pepper.
Toss the vegetables thoroughly until they are evenly coated with the oil and herb mixture.
Spread the seasoned vegetables in a single layer on the prepared baking sheet, leaving space in the center.
Season the chicken breast with a small pinch of salt and pepper, then place it in the center of the baking sheet.
Roast for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are golden and tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing it to serve alongside the roasted vegetables.