Preheat the oven to 425°F.

Line a half sheet pan with parchment paper.

In a small bowl, whisk together the olive oil, parsley, paprika, and garlic powder.

Dice potatoes into 3/4-inch pieces. Place in a gallon-sized zip-top bag. Drizzle 2 tablespoons of the olive oil mixture into the bag. Sprinkle in 1/2 teaspoon salt and 1/4 teaspoon black pepper. Seal the bag and shake to evenly coat the potatoes in oil and seasonings.

Transfer the potatoes to the sheet pan. Do not discard the zip-top bag.

Roast the potatoes on middle rack of oven until they are just able to be pierced with a fork, but not soft, 10 minutes.

Cut the vegetables into uniform pieces. For vegetables like broccoli and cauliflower, cut into 1-inch florets. Slice carrots 1/4 inch thick. For zucchini and summer squash, slice 1/2 inch thick. Cut bell peppers or onions into 1 inch strips. Halve Brussels sprouts, etc. Place the vegetables in the zip-top bag. Drizzle 1 1/2 tablespoons of the olive oil mixture into the bag. Sprinkle in 1/2 teaspoon of salt and 1/4 teaspoon black pepper. Seal the bag and shake to evenly coat the vegetables in oil and seasonings.

Remove baking sheet from oven. Use a rubber spatula to push the potatoes to one side of the baking sheet. Transfer the vegetables to the opposite side of the sheet.

Return the baking sheet to oven and roast the potatoes and vegetables on middle rack for 5 minutes. While vegetables roast, prepare the chicken.

Place the chicken breasts in the zip-top bag. Drizzle the remaining 1/2 tablespoon of the olive oil mixture into the bag. Sprinkle in 1 teaspoon of salt and 1/4 teaspoon black pepper. Seal the bag and shake to evenly coat the chicken in oil and seasonings.

Remove the sheet pan from the oven. Transfer the chicken breasts to the center of the baking sheet, arranging the potatoes and vegetables around the perimeter.

Return the baking sheet to the middle rack of oven and roast for 12 minutes.

Open the oven door. Using a rubber spatula, stir the potatoes and vegetables. Flip the chicken breasts. Continue roasting until the chicken reaches an internal temperature of 165°F, the vegetables are tender, and the potatoes are browned and crisp, about 5 minutes.

Check to see that dish is done. Remove from oven or add time as needed.

Sprinkle chicken and vegetables with fresh parsley, if using, and serve. Refrigerate leftovers for up to 3 days.