Thinly sliced steak and chopped onions cooked on a sizzling grill then mounded in a roll, topped with Cheez Whiz and doused with South Philly attitude.
The exact ingredients have varied over the years, but connoisseurs of the Philadelphia cheesesteak line up around the clock at Pat's King of Steaks for a sandwich invented by Pat and Harry Olivieri.
Harry Olivieri died Thursday of a heart attack at AtlantiCare Regional Medical Center in Pomona, N.J., a hospital spokeswoman said. He was 90.
Before Pat's King of Steaks, the Olivieri brothers ran a hot dog stand in South Philadelphia during the Depression.
As the story goes, one day in 1933, Pat sent his younger brother Harry to the nearby Italian market to buy some steak, because they were tired of eating hot dogs for lunch. They chopped the steak and grilled it with some onions, then slapped the concoction on a hot dog bun.
One of their regular customers, a cabdriver, happened by and insisted on having one of the steak sandwiches, undeterred by the brothers' protests that this was their lunch. The cabby loved it, and the Olivieris decided to switch from hot dogs to steak sandwiches.
The cheese didn't come until later, when a cook added provolone in the 1950s. Cheez Whiz was added to the menu in the 1960s, and Philadelphia natives seem to prefer the processed orange cheese version.
These days, the basic ingredients can be dressed up with various condiments -- homemade dill relish, potent hot sauce, cherry peppers. Even canned mushrooms.
Twenty-four hours a day, 362 days a year -- they close on Thanksgiving, Christmas and Easter -- a line forms around a tiny building in a gritty neighborhood of red brick storefronts and double-parked cars.
Residents and tourists who come for paper-wrapped Philly cheesesteaks and sodas can study the wall of celebrity photos before taking seats at the no-frills picnic tables. Politicians, athletes, singers and actors flock to this fast-food mecca, joining neighborhood toughs and wide-eyed out-of-towners in a line that snakes to the cash-only counter.
A plaque showing the exact spot where Sylvester Stallone, as Rocky Balboa, stood and ate a Pat's cheesesteak is embedded in the pavement.
For the uninitiated, a sign explains the drill: with or without onions; specify provolone, American or Cheez Whiz; have your money ready; go to the back of the line if you make a mistake.
Purveyors of what has become a cultural institution populate Philadelphia. Across the street from the Olivieris' humble stand is rival Geno's Steaks, which also has a devoted following in the Italian American community, and across the city at the Reading Terminal Market is Olivieri's Prince of Steaks, run by cousin Rick.
Pat and Harry were content to reign over their small strip of crowded sidewalk on Passyunk Avenue, and Harry lived in South Philly nearly all of his life, until his deteriorating health forced him to move to his daughter Maria's home in New Jersey. Pat died in 1970.
Harry Olivieri was the youngest of three sons born in Philadelphia to Italian immigrants Michael and Maria Olivieri. The family returned to Italy for a few years, then moved back to the city.
Harry learned the carpentry trade and worked in construction and at the sidewalk stand before he and Pat switched to making steak sandwiches full time.
In addition to his daughter, Olivieri is survived by his wife, Anna; son, Frank; four grandchildren; and seven great-grandchildren.
As Frank Olivieri, who now runs the business with his son Frank Jr., said in 1980: "People come to Philadelphia to go to Pat's and see the Liberty Bell ... in that order."