Cook potatoes 10 minutes in a pot of rapidly boiling salted water. Drain and set aside.
Melt butter and blue cheese; add rosemary. Combine partially cooked potatoes and butter mixture and place on an ungreased baking sheet. Bake in preheated 375 degree oven 20-25 minutes. Remove from oven and sprinkle with parsley, salt, pepper, and cayenne. Mix well.