Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Trim the ends of the Brussels sprouts and cut them in half lengthwise to ensure they get maximum surface area for browning.
Toss the halved sprouts on the baking sheet with 0.5 tbsp of olive oil, 0.125 tsp of sea salt, and 0.125 tsp of black pepper.
Roast the sprouts for 20-25 minutes, tossing halfway through, until the outer leaves are dark, charred, and crispy.
While the sprouts roast, season the chicken breast evenly on both sides with the garlic powder and the remaining salt and pepper.
Heat the remaining 0.5 tbsp of olive oil in a skillet over medium heat and sear the chicken for 6-7 minutes per side until golden and cooked through.
In a small saucepan, whisk together the balsamic vinegar and honey over medium-low heat for 3-5 minutes until the mixture reduces into a thick, syrupy glaze.
Slice the chicken breast and serve it alongside the crispy sprouts, drizzling the warm balsamic glaze over the entire plate before serving.