Step 1: Preheat the Oven and Prepare the Baking Sheet

1. Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper or lightly grease it with olive oil. Using parchment paper prevents sticking and makes cleanup easy.

Step 2: Slice and Prepare the Potatoes

1. Wash the potatoes thoroughly and pat them dry. There’s no need to peel them, as the skin adds extra texture and nutrients.
2. Slice each potato into rounds approximately 1/2 inch thick. Aim for even thickness to ensure they cook evenly.

Step 3: Season the Potatoes

1. In a large mixing bowl, combine the olive oil, melted butter, Parmesan cheese, garlic powder, onion powder, smoked paprika, thyme (or rosemary), salt, and black pepper.
2. Add the potato slices to the bowl, tossing until they are well-coated in the oil, butter, cheese, and seasonings.

Step 4: Arrange on the Baking Sheet

1. Arrange the potato slices on the prepared baking sheet in a single layer, ensuring they don’t overlap. This helps them crisp up evenly.
2. Sprinkle any remaining Parmesan mixture over the tops of the potatoes for an extra layer of cheesy goodness.

Step 5: Bake the Potatoes

1. Place the baking sheet in the preheated oven and bake for 20 minutes. After 20 minutes, flip each potato round carefully using a spatula or tongs to ensure even browning.
2. Continue baking for an additional 15-20 minutes, or until the potatoes are golden brown and crispy on the edges.

Step 6: Garnish and Serve

1. Remove the potatoes from the oven and sprinkle with freshly chopped parsley or rosemary for a burst of color and flavor.
2. Serve the Oven Crispy Parmesan Potatoes hot, with a side of sour cream or Greek yogurt dip if desired.