The chef explained that even the thick, crusty honeycombed bread he was serving (made with a yellow flour from the island of Lemnos) was not something you find in America — not even in the Greek places in Astoria. With a quick flourish, Mr. Soultanos pulled out a Terra Ambera, a natural wine from Lemnos made from white muscat grapes. The flavor was flowery, like a mouthful of roses.

“I’m in love with this wine,” Mr. Poulmentis said. “It’s beautiful.” The small crowd agreed and drained their glasses. Mr. Soultanos explained that it’s an orange wine, from white grapes but made like a red wine, with skin intact, the tannins producing the more robust, spicy flavor.

Mr. Soultanos and his business partner Maria Bakalopoulou had worked with Mr. Poulmentis at Theo’s Restaurant and Oyster Bar, his former gig on the Upper East Side, and though they hadn’t tasted any of the new dishes before, they knew what to expect. Mr. Poulmentis has hosted a cooking show on Greek cable, NGTV, and cooked at the White House as a guest chef for President Barack Obama in 2012.

“Especially when someone is setting up a new restaurant, we have to work the wine list from scratch,” Ms. Bakalopoulou said. “Niko trusts us. And we believe in him.”

Dishes sampled that day included a tuna tartare, enlivened with the small green seeds of the unusual finger lime, which pop in your mouth like citrus-flavored caviar when bitten. Smoked mackerel with bulgur and tiny red peppers known as sweety drops — was smokey and salty, and like a risotto, but served cold. The dish was matched by a white from Santorini that one of the other experts, Brian McCoy of Verity Wine, suggested, and a light retsina, with traces of pine resin.

Though the Greeks have one of the longest winemaking histories in Europe, few restaurants carry Greek wines simply because they’re unfamiliar with them. The chef and importers said they want to change that by showing off the different regions of Greece, the different grapes and different soils, as well as the varied climates.