At Chez Shack, fine food meets island attitude

VIEQUES, Puerto Rico -- "I'm sorry I've been so busy tonight," says our perpetually smiling, spiky-haired waiter as he sets down yet another round of the high-octane house punch. "I usually have time to sit and talk."

That we didn't expect (or ask) him to do so doesn't matter any more than that we had never met him. A certain kind of refined informality is the paradox that pretty much sums things up at Chez Shack.

Proudly run-down and rife with tropical bohemia, the place is an island institution for Canadian and American expats and tourists (many of whom hail from Boston) who come for the island lore almost as much as for the food. Owner Hugh Duffy is said to have helped launch the Mamas and the Papas in the 1960s, employing them at his former St. Thomas restaurant, Duffy's Love Shack. Then there's the scene itself: a cluster of connected, open-air shacks tucked behind a rain forest area that genuinely feels like the middle of nowhere.

The surprisingly sophisticated food, meanwhile, feels a bit like everywhere. Imagine a collision of nearly every tropical-latitude ingredient with French, Italian, and American cooking techniques -- all of it heavy on the seafood, light on the pretense. If the East Coast Grill were in the tropics instead of Cambridge, it would be just like this.

In fact, chef Tony Casino lived in Boston for years and is an alum of both East Coast Grill and the South End's Tremont 647. His food has a lot in common with the creations of his former bosses, Chris Schlesinger and Andy Husbands, respectively.

"We do a lot of classical international cooking but adapt it to what fresh foods I can get here on the island," Casino says. "I try and substitute fruit for fresh tomatoes, for example, since they can be hard to come by. Or use pickled tomatoes instead. Like in the grilled pork loin, we'll use pickled tomatoes with roasted onions, so you get a balance of salty and sweet."

Another example: the pan-seared duck breast, its juicy meat cut with spicy grilled chorizo and the sweet-tart flavors of peach and orange relish. Instead of standard fries, Casino piles on thin and crispy yucca frites.

Seafood, though, is nearly always front and center at the restaurant. The stew of plump, sweet shrimp and scallops (or "S & S," as regulars call it) is heaped with noodles in a deep bowl, steamed in a coconut broth zapped with chiles and lime. A plate of braised red snapper comes swimming in a light tomato broth with roasted red peppers and scalloped potatoes, with a thin layer of crisp-edged bacon in its center. This is food created in the brain but cooked from the gut. It's worldly but not precious, educated but not studied -- the very definition of refined informality.

So, too, is the rest of Chez Shack. Its pink walls are strung with Christmas lights, dotted with painted flower pots, and made a backdrop for steel bands every Monday. On quieter nights, diners are entertained by the sound of peeper frogs from the neighboring forest mixed with recorded Motown tunes. They linger over desserts like the grilled banana split with molasses butter and chocolate passion-fruit sauce, and, of course, over drinks with the uncommonly affable wait staff. Chez Shack, Highway 995 (Airport Road), Vieques, Puerto Rico. 787-741-2175. No credit cards. Closed September and October.