Caviar
From Memory Alpha, the free Star Trek reference.
Caviar was a Human delicacy from Earth, although it or the equivalent may have been popular with other species as well. It consisted of unhatched fish eggs.
In 2366, Captain Jean-Luc Picard always kept some real caviar from the Caspian Sea on the USS Enterprise-D for special occasions, such as a buffet with Klingon exchange officer and Worf's brother Kurn, who, however, did not seem to be fond of the delicacy. (TNG: "Sins of the Father")
Captain Picard felt the replicators did not do the dish justice, and always tries to keep some on hand. Q, on the other hand, had a considerably less favorable opinion of the dish. (TNG: "Deja Q")
When Deanna Troi began to suffer from Barclay's Protomorphosis Syndrome, she ordered Ongilin caviar for dinner and claimed she needed something "salty". (TNG: "Genesis")
