Preheat: Preheat the oven to 400°F.
Prepare the Potatoes: Add the potatoes to a large 12x17-inch rimmed sheet pan. Drizzle with 1 tablespoon of the olive oil and sprinkle with ¼ teaspoon of the salt.
Toss to coat and spread in an even layer. Roast for 10 minutes, until beginning to turn golden at the edges.
Season the Chicken: While the potatoes roast, add the chicken to a large bowl with 1 tablespoon of olive oil, ¼ teaspoon of salt, black pepper, granulated garlic, Italian seasoning, and onion powder. Toss to evenly coat, using clean hands to rub the mixture evenly into the chicken.
Add the Chicken: Remove the pan from the oven. Push the potatoes to one side and add the chicken on the other side in a single layer.
Return to the oven and roast for 10 minutes, flip, then roast 10-15 more minutes, or until the chicken is just cooked through and the potatoes are tender and golden.
Make the Garlic Olive Oil: While the chicken roasts, in a small bowl, whisk together 1 tablespoon of olive oil, minced garlic, lemon juice, and ¼ teaspoon of salt.
Finish: Remove the pan from the oven, then drizzle the garlic olive oil evenly over the chicken and the potatoes.
Sprinkle everything with the Parmesan, tossing the potatoes to coat evenly. Return to the oven for 3-5 minutes, until the cheese is melted and beginning to crisp.