Preheat your oven to 400°F and line a baking sheet with parchment paper.
Trim the ends of the Brussels sprouts and slice them in half lengthwise.
Toss the sprouts on the baking sheet with 1 teaspoon of olive oil, sea salt, and black pepper.
Roast the sprouts for 20 minutes, tossing halfway through, until they are tender and the outer leaves are crispy.
While the sprouts roast, heat the remaining 1 teaspoon of olive oil in a skillet over medium-high heat.
Season the chicken breast and sear for 6-7 minutes per side until the internal temperature reaches 165°F.
In a small saucepan over low heat, whisk the balsamic vinegar and honey together, simmering for 3-5 minutes until it thickens into a syrup.
Toast the walnuts in a small dry skillet over medium heat for 2 minutes until they smell nutty and fragrant.
Slice the chicken and plate it with the roasted sprouts, then finish by topping with toasted walnuts and a drizzle of the balsamic glaze.