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

2. Pat the chicken breast pieces dry with paper towels. In a medium bowl, toss the chicken pieces with 1 tablespoon of olive oil, 1/2 teaspoon of garlic powder, 1/4 teaspoon of dried oregano, 1/4 teaspoon of salt, and 1/8 teaspoon of black pepper until evenly coated. Spread the seasoned chicken in a single layer on one half of the prepared baking sheet.

3. Wash the asparagus spears and snap off the woody ends. In the same bowl, toss the trimmed asparagus with the remaining 1 tablespoon of olive oil, 1/2 teaspoon of garlic powder, 1/4 teaspoon of dried oregano, 1/4 teaspoon of salt, and 1/8 teaspoon of black pepper. Arrange the seasoned asparagus in a single layer on the other half of the baking sheet, next to the chicken.

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

5. After 10 minutes, carefully remove the baking sheet from the oven. Using tongs, flip the chicken pieces and gently toss the asparagus to ensure even cooking and browning. Return the baking sheet to the oven and continue roasting for another 10-15 minutes, or until the chicken is cooked through (internal temperature reaches 165 F / 74 C) and the asparagus is tender-crisp.

6. Once cooked, remove the sheet pan from the oven. If desired, squeeze fresh lemon juice over the chicken and asparagus for a bright, zesty finish. Garnish with chopped fresh parsley before serving immediately.