[3] The cheesesteak was developed in the early 20th century "by combining frizzled beef, onions, and cheese in a small loaf of bread", according to a 1987 exhibition catalog published by the Library Company of Philadelphia and the Historical Society of Pennsylvania.

[4] Philadelphians Pat and Harry Olivieri are often credited with inventing the sandwich by serving chopped steak on an Italian roll in the early 1930s.

[5][6] The exact story behind its creation is debated, but according to many accounts, Pat and Harry Olivieri originally owned a hot dog stand, and on one occasion, decided to make a new sandwich using chopped beef and grilled onions.

[15] On a lightly oiled griddle at medium temperature, the steak slices are quickly browned and then scrambled into smaller pieces with a flat spatula.

[16] Common additions include sautéed onions, grilled mushrooms, ketchup, hot sauce, salt, and black pepper.

[17] One source writes that "a proper cheesesteak consists of provolone or Cheez Whiz slathered on an Amoroso roll and stuffed with thinly shaved grilled meat,"[18] while a reader's letter to an Indianapolis magazine, lamenting the unavailability of good cheesesteaks, wrote that "the mention of the Amoroso roll brought tears to my eyes.

"[19] After commenting on the debates over types of cheese and "chopped steak or sliced", Risk and Insurance magazine declared, "The only thing nearly everybody can agree on is that it all has to be piled onto a fresh, locally baked Amoroso roll.

[27] According to Kosuke Chujo, who runs a cheesesteak shop in Japan, the cheese "was very creamy and delicious with the perfect balance of salt".