Cook the potato cubes half cooked in salted water (approx. 10 min.); Drain and set aside. Melt the butter and cheese together and add the garlic and rosemary.
Mix the potatoes with the cheese butter and spread out on an ungreased baking sheet. Bake in a preheated oven (190 ° C) for 20 to 25 minutes.
Season to taste with parsley, salt, pepper and cayenne pepper and mix everything well. Apply immediately.