Hungry shoppers are being offered the chance to eat a gourmet sandwich, but the £85 price tag might be too much for some to swallow.
Will the bacon sarnie ever seem the same again?
The McDonald sandwich - named after its creator Scott McDonald, the chef at London department store Selfridges - is said to be the world's most expensive.
Its cost is down to the Wagyu beef that makes up most of the filling, packed in a 24-hour fermented sour dough bread.
There have been at least five advance orders placed for the 21oz (595g) meal.
Wagyu cattle are one of the most expensive breeds in the world.
The Japanese cows are raised on a special diet, including beer and grain.
They are supposed to be regularly massaged with sake, the Japanese rice wine, to tenderize the flesh.
Mr McDonald denied his creation was a "sandwich for snobs", saying its beauty was in its simplicity.
"The flavours marry, it's not complicated - albeit a little bit rich," he told BBC London.
Food and catering director at Selfridges on Oxford Street, Ewan Venters, who commissioned the sandwich, said they expected it to be a hit with local "foodies".
"I think if you are a food lover, this represents great value for money," he said.
"Some of the finest ingredients from around the world have been used to create this fabulous sandwich."
The ingredients of the sandwich are: Wagyu beef, fresh lobe foie gras, black truffle mayonnaise, brie de meaux, rocket, red pepper and mustard confit and English plum tomatoes.