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 slice them in half; mince the garlic clove.
In a large bowl, toss the Brussels sprouts with half of the olive oil, half of the sea salt, and half of the black pepper.
Season the chicken breast with the remaining olive oil, salt, and pepper.
Place the chicken and Brussels sprouts on the prepared baking sheet in a single layer, ensuring the sprouts are cut-side down for maximum caramelization.
Roast for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the sprouts are tender and charred.
While roasting, whisk together the balsamic vinegar, honey, and minced garlic in a small saucepan over medium heat.
Simmer the balsamic mixture for 3-5 minutes until it thickens into a syrupy glaze.
Remove the tray from the oven, transfer the sprouts to a bowl, and toss them with the warm balsamic glaze before serving alongside the roasted chicken.