Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Prepare the vegetables by trimming and halving the Brussels sprouts and peeling and slicing the carrots into 1/2-inch thick rounds.
Pat the chicken breast completely dry with paper towels to ensure a golden-brown sear, then slice into even 1-inch strips.
In a large mixing bowl, toss the chicken, Brussels sprouts, and carrots with the extra virgin olive oil until everything is well-coated.
Sprinkle the dried thyme, dried rosemary, garlic powder, sea salt, and black pepper over the mixture and toss again to distribute the aromatics evenly.
Spread the chicken and vegetables in a single layer on the prepared baking sheet, ensuring they aren't crowded so they roast rather than steam.
Roast in the center of the oven for 20-25 minutes, tossing halfway through, until the chicken reaches an internal temperature of 165°F and the vegetables are tender.
Remove from the oven and let the chicken rest for 3 minutes before serving to keep it juicy.