Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into uniform 1-inch cubes to ensure even roasting and consistent texture.
In a large mixing bowl, combine the chicken cubes, broccoli florets, bell pepper strips, and sliced carrots.
Mince the garlic cloves finely and add them to the bowl along with the olive oil, rosemary, thyme, sea salt, and black pepper.
Toss the ingredients thoroughly until every piece of chicken and vegetable is evenly coated in the oil and seasonings.
Spread the mixture in a single layer on the prepared baking sheet, ensuring the pieces are not overlapping so they roast rather than steam.
Roast for 20 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and lightly browned.