Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Peel the carrots and parsnips, then chop them into uniform 1-inch cubes to ensure even roasting.
Mince the garlic cloves finely.
In a large mixing bowl, combine the chicken breast, chopped carrots, and parsnips.
Drizzle the mixture with olive oil and add the minced garlic, dried rosemary, dried thyme, sea salt, and black pepper.
Toss all ingredients thoroughly until the chicken and vegetables are evenly coated in the oil and aromatics.
Spread the mixture in a single layer on the prepared baking sheet, giving the pieces enough space to roast properly.
Roast for 25 to 30 minutes until the chicken reaches an internal temperature of 165°F and the vegetables are tender and golden brown.
Remove from the oven and allow the chicken to rest for 5 minutes before slicing.
Serve the sliced chicken breast alongside the roasted root vegetables for a complete, clean meal.