Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Pat the chicken breast dry with paper towels and slice it into even 1-inch bite-sized pieces.
In a large mixing bowl, whisk together the olive oil, lemon juice, lemon zest, minced garlic, rosemary, thyme, salt, and pepper.
Add the chicken pieces, broccoli florets, and sliced carrots to the bowl, tossing well until every piece is thoroughly coated in the herb mixture.
Spread the chicken and vegetables in a single layer on the prepared baking sheet, ensuring they are not overcrowded so they roast rather than steam.
Roast in the center of the oven for 18 to 22 minutes, or until the chicken is cooked through and the vegetables are tender with slightly caramelized edges.
Remove from the oven and let rest for 2 minutes before serving to allow the juices to redistribute.