Delmonico steak (alternately steak Delmonico) refers to both a cut of beef and a presentation of steak dinner prepared from it, made world-famous by Delmonico's Restaurant in New York City during the mid 1800s.There is controversy as to exactly which cut of steak was originally used by Delmonico's Restaurant. There are at least eight different cuts which are claimed to be the original for the Delmonico Steak. According to some sources, the original Delmonico steak was a boneless top sirloin, almost two inches thick with delicate marbling and cooked rare to well done (depending on the request of the diner).Delmonico's steak may now, in the 21st century, refer to other cuts, prepared differently in different parts of the USA. This wider variety of beef cuts may be broiled, fried, or grilled. Some of the steak cuts now commonly referred to as Delmonico steak include:In addition to the steak, the original meal also included a potato dish, known as Delmonico's potatoes, prepared by making a baked mashed potatoes-like dish topped with grated cheese and buttered breadcrumbs. The dish was then baked until golden brown and served steaming.