"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.

The elusive mushrooms grow underground and are the world's tastiest and most expensive edible fungi. Before long, Liza comes to an abrupt stop at the base of an oak tree, her sniffer goes into overdrive and she proceeds to dig frantically. Tail wagging, Liza returns to Sara offering up the 25-gram black truffle gently transported in her mouth.

"Pridna, pridna," (good girl, good girl), says Sara in thanks while taking the truffle and showing it around.

Today, Liza and Sara have an entourage. My wife and I are part of a group of 16 passengers from the Viking Sky cruise ship who signed up for the Truffle Hunting in Slovenia excursion during a 10-day Mediterranean journey from Athens to Venice. We're half-walking-half-running behind Liza and Sara as they go about their business, peppering Sara with questions and snapping photos all the way. Truffle hunting may have originated in France with fungus-finding pigs, but Slovenia has refined this romantic form of food gathering by throwing dogs into the equation.

"Dogs find the truffles and bring them to you. Pigs want to eat them," says Sara with a laugh. "We also use only female dogs, mostly Labrador retrievers, because they have incredible noses and are more focused than the males, who are lazy and easily distracted."

Touche.

As such, with dedicated concentration, Liza deftly locates four more truffles in short order and doesn't switch off until Sara gives the command to do so. While hunting, Liza is determined and ignores all humans expect Sara. Off-duty, the dog is an affable softie, seeking pats from all on the excursion. Liza is one of only 30 specially-trained truffle hunting dogs in Slovenia, the tiny country on the Adriatic Sea sandwiched between Italy to the north and Croatia to the south. Slovenia is not to be confused with Slovakia the other nearby Eastern European nation.

It's fitting our hunt is conducted just outside Rodica Winery because anything made with truffles magically matches wine. As such, owner and winemaker Marinko Rodica greets us with glasses of his sparkling wine fashioned from the Slovenian-native grape, Malvazija, paired with slices of crusty bread simply topped with a drizzle of olive oil, from Slovenia, of course, and a pencil-shaving-sized bit of black truffle. Truffles are so aromatic and flavorful that a little goes a long way. More wine and truffle cuisine follows as a still wine made with Malvazija is matched to truffle-infused salami and cheese.

A plate of Istrian fuzi pasta crowned with truffle shavings is also served with Malvazija and veal in a truffle sauce is paired with the Reserve Refosk The meal is finished sans truffles with a delicious apple strudel dessert. Viking, long known as the dominant player in European river cruising, has taken ocean cruising by storm with three 930-passenger luxury ships, Viking Star, Viking Sea and the newest, Viking Sky, which we cruised on. Three more Viking ocean vessels will come on stream later this year, 2018 and 2019. All cabins have balconies, the cruises are all-inclusive with beer and wine included at meals and one excursion included in every port.

Our cruise also stopped at the Greek islands of Santorini for more wine tasting and Corfu for mountain biking; Dubrovnik, Croatia to follow in the footsteps of TV's Game of Thrones, which is partially shot in the city; and Kotor, Montenegro to hike the medieval-city wall. To extend the indulgence pre-and-post cruise we stayed at the Grande Bretagne in Athens and the Danieli in Venice, which are both part of Marriott International's The Luxury Collection. We also splurged to fly business class on Air Canada's new 787-9 Dreamliner to and from Frankfurt with connections to Athens and Venice so we could have lie-flat seats for sleeping to arrive rested and ready to cruise.

Check out VikingCruises.com, AirCanada.com, and TheLuxuryCollection.com