Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Trim the ends off the Brussels sprouts and cut them in half. Cut the chicken breast into 1-inch bite-sized cubes.
In a large bowl, toss the chicken and Brussels sprouts with the extra virgin olive oil, sea salt, black pepper, and garlic powder until evenly coated.
Spread the mixture in a single layer on the prepared baking sheet, ensuring the sprouts are cut-side down for maximum caramelization.
Roast for 20 to 25 minutes, tossing halfway through, until the chicken is cooked through and the sprouts are tender with charred edges.
While roasting, whisk together the balsamic vinegar and honey in a small bowl to create the glaze.
Remove the tray from the oven, drizzle the balsamic glaze over the hot chicken and sprouts, and toss gently to coat before serving.