Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Peel and chop the sweet potato and carrots into 1/2-inch cubes, and break the broccoli into small, bite-sized florets.
Mince the garlic cloves finely and cut the chicken breast into 1-inch cubes so they cook at the same rate as the vegetables.
In a large mixing bowl, combine the chicken, sweet potato, carrots, broccoli, and minced garlic.
Drizzle with olive oil and sprinkle with dried rosemary, dried thyme, sea salt, and black pepper.
Toss everything thoroughly until the chicken and vegetables are evenly coated in oil and herbs.
Spread the mixture in a single layer on the prepared baking sheet, ensuring the pieces aren't too crowded.
Roast for 20-25 minutes, tossing the ingredients halfway through, until the chicken is cooked through and the vegetables are tender with caramelized edges.