Bring a pot of salted water to a boil. Add as many cleaned, unpeeled potatoes as you wish, then boil for 10-15 minutes or until fork-tender. Cooking times may vary depending on the variety and size of potatoes.
While the potatoes are boiling, preheat the oven to 450° F.
Line a baking pan with foil or use a Silpat mat. Brush the pan with 1 tablespoon olive oil.
When the potatoes are fork-tender, remove them from the pot of water and drain. Let them sit for a minute until they are dry. Place the potatoes on the prepared pan and smash them with a potato masher or a glass jar. Smash to about 1/2-inch thickness
Drizzle the tops of each smashed potato generously with the remaining olive oil.
Sprinkle potatoes with kosher salt, fresh ground black pepper, and your choice of fresh chopped herbs. (Dried herbs work as well if you don't have fresh)
Bake for 15-20 minutes, remove from the oven, and add the Parmesan cheese. Return to the oven and continue cooking for 5-10 minutes or until the cheese is melted and the potatoes are golden and crispy.