1. Preheat your oven to 400 F (200 C). Line a large baking sheet with parchment paper for easy cleanup.

2. In a large bowl, toss the trimmed and halved Brussels sprouts with 1 tablespoon of olive oil, 1/4 teaspoon of salt, and 1/8 teaspoon of black pepper. Spread them in a single layer on one half of the prepared baking sheet.

3. In the same bowl, toss the cubed chicken with the remaining 2 tablespoons of olive oil, 1/4 teaspoon of salt, and 1/8 teaspoon of black pepper. Arrange the chicken in a single layer on the other half of the baking sheet, next to the Brussels sprouts.

4. Place the baking sheet in the preheated oven and roast for 10 minutes.

5. While the chicken and Brussels sprouts are roasting, whisk together the Dijon mustard, honey, apple cider vinegar, garlic powder, and paprika in a small bowl until well combined.

6. After 10 minutes, remove the baking sheet from the oven. Drizzle half of the honey mustard glaze over the chicken and the other half over the Brussels sprouts. Toss both the chicken and Brussels sprouts directly on the pan to ensure they are evenly coated. Return the pan to the oven and continue roasting for another 10-15 minutes, or until the chicken is cooked through (internal temperature of 165 F or 74 C) and the Brussels sprouts are tender-crisp and slightly browned.

7. Once cooked, remove the sheet pan from the oven. Serve hot and enjoy your delicious, easy dinner!