Le Viet (two bells) sets an ambitious standard for Vietnamese dining

There is a deep-seated suspicion, for some reason, of authentic Vietnamese restaurants that dare to go upscale. Adventure eaters and aficionados will tend to assume that any place with black leather banquettes and sleek, dark wood paneling cannot possibly be as genuine as the bare-bones pho halls and all-purpose banquet venues that line Washington Avenue.

I've seen this play out in Chinatown, too, where more than a few restaurants saw some of their hard-core faithful drift away - at least temporarily - after a room upgrade and a modest price increase. People may forget, because it's been a while since its reinvention, but Vietnam Restaurant was one of those, too, after transforming from a modest formica palace into a haven of Indochine chic, and, subsequently, one of our enduring touchstones of ethnic eats.

Is Bruce Cao's handsome new Le Viet on South 11th Street the latest to defy the old stereotypes with a tandem package of good cooking and cool ambience?

Add the unexpected touch of a rolling dry-ice mist, a giant spider puppet climbing the wall, and strobe lights stoking the very un-Vietnamese spirit of Halloween on one of my early visits, and the confusion only mounts.

"We always did the holidays at home in a big way," says Cao, a former Web designer who hired his father, Sinh Cao, to be the chef.

When the mist blows away, it's clear Le Viet has a smart uptown look that stands apart from its gritty Washington Avenue neighbors - including such personal favorites as Nam Phuong and Pho 75 just a half-block south, wedged into perpetually frenetic strip malls. Located just above the bustle in a stand-alone building that was formerly an auto mechanic's garage, the space has been totally transformed with layered stone walls, smoked glass framing the open kitchen, and lights that dangle like bubbles behind the plate-glass facade. Forsythia blooms along the low wall dividing the dining room from the future bar (it's still BYOB). Only the two flat-screen TVs there flashing sports distract from the mood of sophistication.

When it comes to the menu, though, chef Sinh, a Knave of Hearts stalwart before opening his own bare-bones Washington Avenue nook, the Hang Sinh Duck House, cooks from the heart of pure tradition, with elegant presentations, good ingredients, and a northern Vietnamese palate that varies slightly from the southern flavors more common in Philly.

His take on pho noodle soup, for example, a dish that originated in the colder north, features less sweetness in the broth than its Southern counterparts. But its richly steeped oxtail brew is inflected with notes of star anise and ginger that add mysterious depth to the snappy rice noodle threads and frilly ribbons of tripe, chewy pads of thin flank steak, tender meatballs, and the crunchy sprouts I add, with herbs, jalapeño and lime. A fine sheen of molten beef fat beads atop each spoonful and coats my lips, allowing me to savor this meal in a bowl - just $5.95! - long after I've moved on.

Sinh crafts a number of other worthy distinctive soups: a chicken pho actually steeped from chickens (as opposed to the doctored-up beef broth many pho halls serve); a deeply funky seafood stew (bun mam) amped with lemongrass, shrimp paste and bitter melon (not for everyone); and a Hanoi-style crab soup that tastes like tomato consommé topped with a froth of crabmeat, whipped egg, and creamy orange crab fat.

Despite the restaurant's almost suburban good looks and a cashmere p.m. crowd that can seem more Society Hill than Asian South Philly, Sinh doesn't hide flavors that might intimidate the newbies. The charming young English-fluent servers can ably guide you to your appropriate speed. But for those who want pork blood cubes and tendon for their pho, or hot pot casseroles with quail eggs and pork belly bubbling up from their tangy dark broth, Le Viet is happy to oblige.

Even Sinh's masterful cold salads of shredded green papaya and liver jerky, lotus stalks with pork and shrimp, or paper-thin slices of bitter melon deliver a bracing zap of citrus sour, sweet hoisin, fish sauce funk, and minty herbs that makes my taste buds hum at a higher frequency than I knew they had.

When I think of the dishes that would draw me back to Le Viet, the most exceptional flavors reside in the "appetizer" section of the vast, 77-item dinner menu. Sinh's standard spring rolls ("cha gio") are just so-so. But his clever variation called "cha gio re" is memorable, replacing the usual one-dimensional pastry wrapper with the shattering crunch of a tube made from spun threads of crispy crepe batter. The most unusual here is "hen xuc banh da," a central Vietnamese mince of baby clams blended with onions and ground beef cradled in a speckled rice-cracker bowl that looks like modern art. It was topped with minty basil and crushed peanuts and tossed in a complex sweet and sour oyster sauce. I broke off cracker shards and devoured it as if it were some divinely exotic clam stuffing.

There are also some fantastic sweet and savory nibbles to be found, such as roasted quails lacquered in a hoisin-oyster sauce that tingles with lemongrass. Or the tender little rings of spare rib served in a clay pot casserole. Or the mahogany-sauced morsels of buttery filet mignon (bo luc lac) that light up on the tongue when dredged in the deceptively simple side sauce of lime juice squeezed into a dish of salt and pepper. Or the addictive Pop's chicken wings, apparently as popular in Vietnam as in the United States, which have a garlicky bite beneath their deeply caramelized sesame-hoisin glaze.

The traditional crepe, made from coconut milk and curry and wrapped around shredded pork and shrimp, has a perfect outer crisp and creamy interior softness. Even the grilled lamb chops starter was a hit, marinated in red wine, sesame, and soy, then splashed with a citrus sauce spiced with sriracha.

Sinh also offers clever little touches to effectively tweak a common dish - like the grilled pork and scallion patties that lend a charry, smoked flavor to the dipping sauce alongside the bun noodles with grilled pork belly (bun cha Le Viet). Or the perfectly crisp rectangle of a noodle boat, bearing a gingery stir-fry of seafood, bok choy, and straw mushrooms.

There were only a few disappointments, including a deep-fried rockfish - at $22, easily the most expensive entrée on a menu that hovers below $15 - that was bland and overcooked despite its spectacular presentation. The "crispy" fried softshells were mushy.

For the most part, though, this food was a delight. And so was Le Viet, which should quickly become a favorite as it sets an ambitious new standard for what Vietnamese dining near Washington Avenue can be.