If there ever was a food-fad on menus that burned ever so bright but flamed out so extravagently it was probably the sun-dried tomato.
At it's peak (circa 1980s/early 90s), you could find it in everything from the pedantic (pizza, pasta, sandwiches) to the exotic (remember crab cakes with sun-dried tomato paste or foie gras wrapped in sun dried tomatoes?) and to just the awful (sun-dried tomato ice cream!).
There are other fads that have come and gone, things like truffle oil, goat cheese, ponzu sauce, etc.
Some have had amazing staying power -- the most immediate that comes to mind is the omnipresent tuna tartar.
What do you guys think are food items that are well into their 15 minutes of fame?
I think pomegrenate is at about 13:45.
Kobe beef is at the 10 minute mark by my estimate.
But I do think that gelato has staying power.