Preheat your oven to 425°F (220°C). A hot oven is key to achieving that crispy texture on the outside of the potatoes.
Wash the small creamer potatoes thoroughly under running water to remove any dirt. Pat them dry with a clean towel. If any potatoes are larger than a bite-sized piece, cut them in half to ensure even cooking.
In a large mixing bowl, combine the potatoes with vegetable oil, salt, and pepper. Make sure each potato is well-coated.
Pour the melted butter over the seasoned potatoes and add the minced garlic. Toss everything together until the potatoes are evenly coated.
Spread the potatoes in a single layer on a rimmed sheet pan. Place the pan in the preheated oven and roast for about 25 to 30 minutes, turning them halfway through for even browning.
Once the potatoes are fork-tender and golden brown, remove them from the oven. Sprinkle with fresh parsley and grated Parmesan cheese while they are still hot.
Transfer the roasted mini potatoes to a serving dish. They are best enjoyed warm, so serve them immediately.