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 lengthwise.
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 they are not overcrowded.
Roast for 20 to 25 minutes, tossing halfway through, until the chicken is cooked through and the sprouts are caramelized and crispy.
While the tray roasts, combine balsamic vinegar and honey in a small saucepan over medium-low heat.
Simmer the balsamic mixture for about 5 minutes until it reduces by half and becomes a thick glaze.
Remove the tray from the oven, transfer to a serving plate, and drizzle the warm balsamic glaze over the top before serving.