White truffle (Tuber magnatum, also called the Alba truffle) is a rare, pungent fungus that grows underground in symbiosis with oak, hazelnut, and poplar tree roots, found almost exclusively around Alba in Italy's Piedmont region. Unlike black truffle (Tuber melanosporum), which can take gentle cooking, white truffle is never cooked; it is shaved raw over warm dishes like pasta, risotto, and eggs just before serving, since heat destroys its garlicky, musky aroma. It is also used to infuse oils and butter. It pairs well with rich, umami ingredients such as Parmesan, butter, cream, and egg yolks, and with root vegetables like potato and celery. Scarcity and difficulty of harvest make it one of the most expensive ingredients in cooking.