The menu at Barclay Prime in Philadelphia boasts luxurious ingredients you would expect of a high-end steakhouse: wagyu ribeye, foie gras and truffled cheese. What you might not expect is that those ingredients are used in the restaurant's Philly cheesesteak. The Barclay Prime Cheesesteak sells for $120 and is the most expensive in America, according to a new episode of CNBC's "Secret Lives of the Super Rich."

This dinner special is no ordinary sandwich. Executive Chef Mark Twersky starts with waygu, a famously tender Japanese beef. The meat costs $75 per pound and is guaranteed with a certificate of authenticity. "This is the money right here, this is the A5 waygu beef," Twersky says. "It's so rich and flavorful." He adds the beef to a sesame roll with foie gras mousse and truffle butter, adding a few extra truffles for good measure.

CNBC | Secret Lives of the Super Rich

Then the sandwich is laden with the Italian Caciotta al Tartufo cheese, which is a blend of cow's milk, sheep's milk and truffles, an opulent upgrade from the usual American slices or provolone.

CNBC | Secret Lives of the Super Rich

Visitors to Barclay Prime who order the dish are also served a half bottle of champagne to pair with the sandwich. "The guests that do have it, hands down are blown away," says Twersky. "[They] always say they never imagined they'd have a cheese steak that tasted like this."

CNBC | Secret Lives of the Super Rich