The truffle (genus Tuber) was an edible fungus native to Earth.
In 2377, after their encounter with the Lokirrim, Seven of Nine replicated an ancient Earth delicacy, foie gras with truffles, and described the sensations of eating it to The Doctor so that he may enjoy it vicariously. (VOY: "Body and Soul")
Later that year, Seven of Nine prepared a meal for Kathryn Janeway, Chakotay, Tom Paris, and B'Elanna Torres. The third course was Luhvian quail with truffle sauce, served with roasted chadre'kab. (VOY: "The Void")
Tellarite Blood truffle biscuit was a type of food prepared with truffles. The confection chocolate truffle was named for its resemblance to this fungus.