A few drops of truffle oil.... 
I've never had truffles or truffle oil. How is it?
Very pungent & earthy ?? More of a smell than a taste in the food ? You probably wouldn't call sniffing the bottle pleasant ? I had a risotto with mushrooms & truffle oil in a restaurant last week which was lovely, so picked up a tiny bottle from M&S to try. It's only olive oil with truffle extract/essence...
From Wiki
Their one-dimensional flavor is also changing common understanding of how a truffle should taste," Daniel Patterson complained in a New York Times article.[3]
Gordon Ramsay has referred to natural truffle oil as "a chef's dream",[4] and to synthetic truffle oil as "one of the most pungent, ridiculous ingredients ever known to [this] chef."
Anthony Bourdain said, "Let it be stated here, unto forever and eternity, [synthetic] truffle oil is not food."[5]
Martha Stewart expressed her dislike of synthetic truffle oil in a 2014 post on Reddit, stating "I think truffle oil is one of the few ingredients that doesn't belong in anyone's kitchen. It's ruinous of most recipes."[6]
Joe Bastianich said, "It’s made by perfumists. It’s garbage olive oil with perfume added to it, and it’s very difficult to digest. It’s bad for you. It’s bad for New Yorkers. It’s bad for the American people. So, stop it.". [7]
