Preheat your oven to 400°F (200°C).
Slice the sweet potato into 1/2-inch rounds or cubes for even roasting, and trim the ends off the Brussels sprouts, halving them if they are large.
In a small bowl, mix the balsamic vinegar with a pinch of salt and black pepper.
Place the chicken breast in a shallow dish and drizzle half of the balsamic mixture over it, allowing it to marinate for about 10 minutes.
On a baking sheet lined with parchment paper, toss the Brussels sprouts and sweet potato with olive oil, a pinch of salt, and black pepper.
Roast the vegetables in the preheated oven for 20-25 minutes or until tender and slightly crispy on the edges, stirring halfway through.
While the vegetables roast, heat a non-stick skillet over medium-high heat. Sear the marinated chicken breast for about 5-6 minutes per side, or until fully cooked and golden.
Once the chicken is near the end of cooking, drizzle the remaining balsamic mixture over the chicken in the skillet, letting it reduce slightly to form a glaze.
Serve the glazed chicken alongside the roasted vegetables, and enjoy your balanced, nutrient-packed meal.