Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper for easier cleanup.
In a large bowl, toss the potatoes with 1 tablespoon of olive oil, 0.5 teaspoon of salt, and 0.25 teaspoon of pepper. Spread the potatoes in a single layer on one half of the prepared baking sheet.
Roast the potatoes for 15 minutes while you prepare the chicken.
In the same bowl, toss the chicken pieces with the remaining 2 tablespoons of olive oil, 0.5 teaspoon of salt, 0.25 teaspoon of pepper, Italian seasoning, and garlic powder.
Remove the baking sheet from the oven. Push the potatoes to one side if needed and arrange the seasoned chicken pieces on the empty half of the sheet pan.
Bake for another 15-20 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and the potatoes are tender.
While the chicken cooks, mix the grated Parmesan cheese and minced garlic in a small bowl.
Remove the sheet pan from the oven. Sprinkle the Parmesan-garlic mixture evenly over the chicken and potatoes. Return the pan to the oven for 3-5 minutes, or until the cheese is melted and lightly golden.
Remove from the oven, garnish with fresh parsley, and serve immediately.
Notes
For crispier potatoes, ensure they are cut into uniform sizes and do not overcrowd the baking sheet. Use two sheets if necessary.
Chicken thighs stay juicier than breasts in this preparation. Adjust cooking time if using thicker cuts of chicken.