Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Pat the chicken breast dry with a paper towel to ensure a beautiful golden sear, then slice into 1-inch bite-sized pieces.
In a large mixing bowl, toss the chicken, broccoli florets, and sliced carrots with olive oil, minced garlic, rosemary, thyme, salt, and pepper until evenly coated.
Spread the mixture in a single layer on the prepared baking sheet, ensuring the pieces aren't crowded so they roast properly rather than steam.
Roast for 18-22 minutes, tossing halfway through the cooking time, until the chicken is cooked through and the vegetables are tender and slightly caramelized.
Remove from the oven and serve immediately while hot, perhaps with a squeeze of fresh lemon for an extra bright finish.