Preheat your oven to 400°F (200°C) and line a large rimmed sheet pan with parchment paper for easy cleanup.
Peel and chop the carrots and parsnips into 1/2-inch thick coins and halve the Brussels sprouts.
In a small bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, minced garlic, rosemary, thyme, salt, and pepper.
Place the chicken breast and prepared vegetables on the sheet pan, then drizzle the lemon-herb mixture over everything, tossing well to coat.
Spread the ingredients into a single layer, ensuring the chicken is not covered by vegetables so it browns evenly.
Roast for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and golden.
Let the chicken rest for 5 minutes before slicing to keep it juicy, then serve alongside the roasted vegetables.