Chef George Mavrothalassitis has traveled — and cooked — the world, so it's not often that he stumbles across something culinarily new.

But earlier this year, when he accepted an invitation to cook aboard a cruise ship in the South Pacific, and stopped off for a few days in Pape'ete, Tahiti, and Bora Bora in the Society Islands, he found himself surprised ... by surprise.

"It is very rare that I see something I was not aware of," said the chef, popularly known as Mavro.

He was so impressed with the purity and simplicity of Tahitian cuisine that he is running a special fixed-price dinner of South Pacific-inspired dishes at his Chef Mavro restaurants.

"When we arrive in Pape'ete, we didn't have too much information so we went to the visitor's bureau and as soon as I arrive, a Tahitian woman is doing a cooking demonstration," Mavro said, still amazed at the coincidence. "I'm serious. Fifteen minutes after I arrive, I am looking at cooking. She showed me how to do everything. It was so easy for me to decide how to do a menu."

His attention was captured by the similarities, and the distinct differences, between food here and food there despite both cuisines largely being based on the same ingredients.

"In Hawai'i cuisine — I'm talking about local cuisine now — you have a very strong Asian influence. Saimin is not Hawaiian. Poke the way we make it is not Hawaiian. But in Tahiti, you have no fusion, just traditional Polynesian cuisine the way it was 2,000 years ago. It is amazing."

This is even though the French colonized Tahiti and many Chinese (descendents of immigrant Hakka laborers) live there, he noted. There are French restaurants and many Chinese grocery stores, but no cross-pollination that he noticed.

"Of course, is not too many recipes but (ethnically) Hawaiian is not too many recipes, either," he said. "What it is is very fresh, very basic. I like the purity, they use the pure ingredients. In Tahiti, to use coconut milk from a can is an insult."

The chef became a passionate fan of the national dish of Tahiti, poisson cru (French for raw fish, although it is properly poisson cru au lait de coco; raw fish with coconut milk), or e'ia ota. Most often made with sashimi-grade 'ahi, the dish is a salad of fish marinated in lime juice, tossed with thinly sliced vegetables (onion, tomato, cucumber, carrots and/or scallions, according to taste) and bathed in fresh coconut milk. Salt, pepper and chilies, perhaps a pinch of sugar to balance the acid, may flavor the dish.

Mavro noted that poisson cru is always made with lime juice, never lemons, which he said are completely absent in Tahiti. He asked for lemon one night for his fish and got lime, for example.

Tahitians, Mavro said, do not use boiling water to extract the coconut milk but simply grate the plentiful, moist coconut meat, wrap it in cloth and squeeze it. And they cut the fish not into chunks, as we do for poke, but in thinnish squares.

This dish is the first of the three on Mavro's special menu. "I am making my poisson cru exactly the way they are making it," he said.

Mavro was amazed at the many ways that coconut and coconut milk comes into play in the Tahitian diet. "If you don't like coconut, you go somewhere else!"

Also memorable: the immense variety of eating and cooking bananas (which they call banana legume), the succulent fresh mahi mahi ("I eat mahi every day, sometimes twice a day, and I never eat it in Hawai'i"), the never-frozen shrimp, the uses for dry land taro.

In that first cooking demonstration, the chef experienced Tahitian-style poe (poi). There are many varieties but this one was made with a mixture of taro, papaya and banana, moistened with coconut milk and a bit of pineapple juice and thickened with tapioca starch.

"It was delicious. This was a recipe I never heard about in my life. The result looks like a pudding, a bread pudding, but they don't use bread," he said.

The proportions are two parts mashed taro to a hefty one part starch so that the dessert holds its shape.

The chef was so taken with the taro poe that he decided to play on that for the dessert for his special dinner, serving a baked taro pudding alongside banana ice cream.

Besides many varieties of fresh fish, Tahitians enjoy fresh local chicken ("Which we don't have here," he lamented, "it's crazy") and pork. The centerpiece of his "Back from Bora Bora" menu is pineapple-glazed Island pork with sweet potato puree and coconut spinach. (In contrast to Islanders —  "find me a local who likes pineapple and I'll give you $20" — Tahitians love pineapple and use it often.)

Mavro said that one reason he may have liked Tahiti so much is that, culinarily, it reminded him somewhat of France, in its devotion to pristine, fresh ingredients and unadulterated regional cuisine. Said the chef: "I like the purity."

To make poisson cru at home:

POISSON CRU

• 1 1/4 pounds sashimi-grade 'ahi tuna, cut into small squares

• Pinch of kosher salt

• 1/4 cup lime juice

• 1 small cucumber, peeled, seeded and cut into strips or cubes or shaved

• 1 ripe tomato, seeded and diced

• 1 tiny hot red pepper, seeded and minced, or a good splash of chili pepper water or a dab of sambal oelek chili paste

• Pinch of fresh-ground pepper

• 1/4 cup coconut milk (preferably fresh-squeezed) or juice of 1 fresh coconut

• 3-4 sprigs green onion, thinly slivered

Place tuna in a large, non-reactive bowl. Sprinkle salt over tuna. Drizzle lime juice over and allow to marinate 5-10 minutes. Add vegetables and chilies, season with pepper and pour over coconut milk. Gently fold mixture. Cover and chill. Taste and correct seasonings. Garnish with green onion and serve.

Variations: Add grated or shaved carrots, diced or shaved red onion or sweet onion, a little minced garlic and/or a pinch of sugar.