Tricastin's black truffles

Black truffle or "Tuber Melanosporum" looks like a black tuber with tiny diamond cutters and finely veined with white in the middle. This prestigious "black diamond", once very common is now rare and expensive. It is considered as one of the best and most refined dishes. In the Tricastin region (West part of Drôme Provençale- 60% of the national production of truffle) black truffle grows under white and green oak trees but is a very capricious production, never certain from one year to another.