Preheat your oven to 400°F (200°C).
In a small bowl, mix together the cheese, garlic powder, paprika, black pepper, oregano, and salt until well combined.
Brush 2 teaspoons of olive oil evenly across the bottom of a 10-inch round baking dish (a cake pan works well).
Evenly sprinkle the cheese mixture over the oiled surface of the dish.
Press the cut sides of the potatoes firmly into the cheese mixture, taking care not to move them once set.
Gently brush the tops of the potatoes with the remaining olive oil.
Roast in the preheated oven for about 30 minutes, or until the tops are wrinkled and the potatoes are just tender when pierced with a fork.
Remove from the oven and let the dish rest for 5 minutes. Break apart any Parmesan crisps that may have formed between the potatoes.
Transfer the potatoes to a serving platter, garnish with fresh parsley, and serve with sour cream on the side for dipping, if desired.
