Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Trim the ends of the Brussels sprouts and cut them in half lengthwise.
In a mixing bowl, toss the sprouts with 0.5 tablespoon of olive oil and half of the sea salt and black pepper.
Spread the sprouts on the baking sheet cut-side down and roast for 20-25 minutes until the edges are deeply browned and crispy.
While the sprouts roast, season the chicken breast with garlic powder and the remaining sea salt and black pepper.
Heat the remaining 0.5 tablespoon of olive oil in a skillet over medium-high heat and sear the chicken for 6-7 minutes per side until the internal temperature reaches 165°F.
In a small bowl, whisk together the balsamic vinegar and maple syrup until well combined.
Remove the roasted sprouts from the oven, drizzle with the balsamic mixture, and toss to coat.
Slice the chicken breast and serve immediately alongside the glazed Brussels sprouts.