Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Trim the ends of the Brussels sprouts and cut them in half vertically.
In a bowl, toss the Brussels sprouts with 0.5 tablespoons of olive oil, half of the sea salt, and half of the black pepper.
Spread the sprouts on the baking sheet in a single layer and roast for 20-25 minutes until the edges are charred and crispy.
While the sprouts roast, season the chicken breast with garlic powder and the remaining salt and pepper.
Heat the remaining 0.5 tablespoons of olive oil in a skillet over medium-high heat and sear the chicken for 6-7 minutes per side until fully cooked.
In a small saucepan, combine the balsamic vinegar and honey over low heat, simmering for 3-5 minutes until it thickens into a glaze.
Slice the chicken and serve alongside the roasted Brussels sprouts, drizzling the balsamic glaze over both before serving.