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

2. Dice the sweet potato into 1-inch cubes. Halve the Brussels sprouts. Cut the red onion into wedges and chop the red and green bell peppers into similar-sized pieces. Uniformity in size helps everything cook through at the same rate.

3. In a large bowl, combine the diced chicken breasts with olive oil, rosemary, thyme, garlic powder, salt, and black pepper. Toss well to ensure the chicken is evenly coated. Add the chopped sweet potato, Brussels sprouts, red onion, and bell peppers to the same bowl. Toss everything together until the vegetables are also lightly coated with the oil and seasonings.

4. Spread the seasoned chicken and vegetables in a single layer on the prepared baking sheet. Make sure not to overcrowd the pan; if necessary, use two baking sheets to allow for proper roasting and browning.

5. Place the baking sheet in the preheated oven and roast for 25-30 minutes. Halfway through the cooking time (around 12-15 minutes), carefully remove the baking sheet from the oven and give the chicken and vegetables a good stir or flip them with a spatula. This promotes even cooking and browning on all sides.

6. The chicken should be cooked through with no pink in the center, reaching an internal temperature of 165 F (74 C). The vegetables should be tender and slightly caramelized at the edges.

7. Once cooked, remove the baking sheet from the oven. Drizzle the chicken broth and apple cider vinegar over the hot chicken and vegetables. This adds a touch of moisture and brightens the flavors.

8. Transfer the meal to serving plates. Garnish with fresh chopped parsley, if desired, for a pop of color and freshness. Serve immediately and enjoy your wholesome fall dinner.