Black winter truffles (tuber melanosporum) are the most aromatic and thus the most prized of the 70 varieties of truffles. Impossible to cultivate, this subterranean fungus grows near the roots of certain trees (primarily the oak but also chestnut, hazelnut, and beech trees); they are found by truffle seekers (truffiers) working with dogs (or sometimes pigs) trained to sniff them out. With truffle pieces, you get the same amount of heady truffle flavor without the exorbitant cost of whole truffles (and you were going to cut them up to use in your recipe anyway, weren't you?)

Next time you're in Paris, be sure to stroll by La Maison de Truffes on the Place de la Madeleine: the smell is intoxicating, even from the sidewalk. You can also visit the Ecomusée de la Truffe in Sorges (Dordogne), which features exhibits in French and English and a unique walk through truffle territory.