Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Peel the carrots and parsnip, then chop them into uniform 1-inch chunks to ensure even roasting.
Finely mince the garlic cloves and strip the fresh rosemary and thyme from their stems, chopping the leaves finely.
In a large mixing bowl, combine the chicken breast, chopped root vegetables, minced garlic, olive oil, rosemary, thyme, salt, and pepper.
Toss the ingredients thoroughly until the chicken and vegetables are well-coated in the herb-oil mixture.
Spread the mixture onto the prepared baking sheet in a single layer, making sure the chicken pieces have space around them to brown.
Roast for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and golden brown.
Remove from the oven and let the chicken rest for 5 minutes before slicing and serving alongside the roasted roots.