We're talking about the truffle, the world's most expensive fungus.
Prices vary each year, but can run to thousands of dollars per pound.
The main clue to truffles' whereabouts is their intoxicating and unforgettable aroma. Black truffles smell intensely earthy, while white truffles emit a sweeter scent. It's really your sense of smell tasting it. In fact, a truffle's scent is an alleged aphrodisiac. Not only are they difficult to find, but truffle harvest time is limited.