Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Peel and chop the carrots and parsnips into 1-inch chunks, and slice the red onion into wedges.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a large mixing bowl, toss the chopped carrots, parsnips, and onions with half of the olive oil, half of the minced garlic, and half of the fresh herbs.
Place the chicken breast on the prepared baking sheet and rub with the remaining olive oil, garlic, herbs, sea salt, and black pepper.
Arrange the seasoned vegetables in a single layer around the chicken on the baking sheet, ensuring they are not overcrowded.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and golden.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure it remains juicy and flavorful.