Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Peel the carrots and parsnips, then slice them into one-inch thick rounds or chunks.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a large mixing bowl, combine the chicken breast, carrots, and parsnips.
Drizzle with olive oil and add the minced garlic, rosemary, thyme, sea salt, and black pepper.
Toss everything thoroughly to ensure the chicken and vegetables are evenly coated in oil and herbs.
Arrange the ingredients in a single layer on the prepared baking sheet, ensuring they aren't overcrowded.
Roast for 25 to 30 minutes, or until the chicken is cooked through and the vegetables are tender and slightly browned.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy.