Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Wash the Brussels sprouts, trim the ends, and cut them in half lengthwise.
Dice the chicken breast into bite-sized, 1-inch pieces.
In a large mixing bowl, toss the chicken and Brussels sprouts with the 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 Brussels sprouts are cut-side down for maximum crispiness.
Roast for 20-25 minutes, tossing halfway through, until the chicken is cooked through and the sprouts are tender with charred edges.
Transfer to a plate and drizzle with the balsamic glaze immediately before serving.