Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Peel and slice the carrots and parsnips into 1-inch thick rounds to ensure they cook evenly.
In a large bowl, toss the sliced root vegetables with 0.5 tablespoon of olive oil, half of the minced garlic, and a pinch of the salt and pepper.
Spread the vegetables in a single layer on the prepared baking sheet and roast for 10 minutes.
While the vegetables are pre-roasting, rub the chicken breast with the remaining olive oil, rosemary, thyme, garlic, salt, and pepper.
Remove the tray from the oven, move the vegetables to the sides, and place the seasoned chicken breast in the center.
Return the tray to the oven and roast for another 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are golden brown.
Remove from the oven and squeeze the fresh lemon juice over the chicken and vegetables before serving.