Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Peel and chop the carrots and parsnips into uniform one-inch pieces to ensure even cooking.
Cut the chicken breast into bite-sized cubes of approximately the same size as the vegetables.
In a large mixing bowl, combine the chicken, carrots, and parsnips.
Drizzle with olive oil and sprinkle the rosemary, thyme, garlic powder, sea salt, and black pepper over the mixture.
Toss everything thoroughly until the chicken and vegetables are well-coated in oil and spices.
Spread the mixture in a single layer on the prepared baking sheet, ensuring pieces are not overcrowded.
Roast for 20 to 25 minutes, or until the chicken is cooked through and the vegetables are tender and lightly browned.
Remove from the oven and let rest for two minutes before serving warm.