Preheat your oven to 400°F.
Trim and halve the Brussels sprouts, then toss them on a parchment-lined baking sheet with 0.5 tbsp of olive oil, garlic powder, sea salt, and black pepper.
Roast the sprouts for 20-22 minutes until the edges are beautifully charred and the centers are tender.
While the vegetables roast, season the chicken breast with a light pinch of salt and pepper.
Heat the remaining 0.25 tbsp of olive oil in a skillet over medium-high heat and sear the chicken for about 6 minutes per side until the internal temperature reaches 165°F.
In a small saucepan over low heat, whisk the balsamic vinegar and maple syrup, simmering for 4 minutes until the liquid reduces into a thick, glossy glaze.
Place the walnuts in a small dry pan over medium heat for 2-3 minutes, tossing frequently until they are fragrant and toasted.
Slice the chicken into strips and combine in a bowl with the roasted sprouts and walnuts, then finish by drizzling the warm balsamic glaze over the top.