"Isci, isci," ring out the shouts in the hills above Koper, Slovenia. Translated the command is, "search, search." The verbal encouragement comes from Sara Kocjancic and is directed at two-year-old yellow Labrador retriever Liza, a truffle-hunting dog extraordinaire. Following instructions, Liza, tail up and snout down, zigzags through the forest in a quest for truffles.