Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Peel the carrots and slice them into half-inch rounds, then trim the ends off the fresh green beans.
Cut the chicken breast into uniform one-inch cubes to ensure even roasting and consistent texture.
In a large mixing bowl, toss the chicken, carrots, and green beans with olive oil, salt, pepper, garlic powder, and fresh thyme leaves.
Spread the mixture in a single layer on the prepared baking sheet, ensuring the pieces are not overcrowded so they crisp properly.
Roast for 20 to 25 minutes until the chicken is cooked through and the vegetables are tender with caramelized edges.
Serve the roasted chicken and vegetables over a bed of warm quinoa for a complete, high-protein meal.