Here are the mechanics (taken from an article posted by Beatriz Acosta at www.clickthecity.com. You will find also the photographs I used here in that article):
"Just inform the people at the counter that you are taking on the Ridiculous Challenge, and they will whip up their timer. Finish the burger within five minutes, ring the bell, and you get a full refund! Yep, a free burger if you can chomp on it before the time is up. And before you go on exclaiming, "That's ridiculous!", it sort of is not, as a good and growing number of people have triumphed over the huge burgers. Burger Avenue has a 'Hall of Fame' of sorts on their wall. They've got photos of the people who gobbled up the burgers in record time, proving that indeed, you can do it!"