From the first cushioned swing of its heavy wooden doors, Sapa feels expensive. The hip design firm AvroKO has retrofitted the soaring, roomy Chelsea space with gauzy hanging lamps, finely tuned diffuse lighting, and an abundance of burnished wood. Raw concrete and brick, acres of unadorned whiteness, and right angles everywhere maintain a warehouse like feel. Trained legions of major and minor wait staff greet guests with brisk professionalism, serve them efficiently if coldly, and remain attentive to any recession in the level of a wineglass. Even if a few gracious details of design and service fall through the cracks, many more are neatly taken care of. The name itself feels expertly engineered: Sapa is the name of a North Vietnamese mountain village, but linguistic ghosts of sap and sapidity haunt the word; sapa is also a sweetly heady Italian syrup made from cooked grape pressings. The restaurant bills its fare as “French Vietnamese,” but nothing so specific can be deduced from its menu, where Southeast Asian influences meld with Chinese, American, and miscellaneous others into the familiar but nonspecific polyglot spoken at creative high-end restaurants worldwide. Chef Patricia Yeo carefully highlights the flavor of excellent ingredients with a couple of well-chosen complements. Her exacting technique, sharpened at AZ, unifies the menu despite itself, making irrelevant such stodgy questions as, “What does a caviar-topped knish have in common with a five-spice-braised pork shoulder?”

A petite binder contains the menu, which is indexed by tabs into categories: Starters, For the Table, Roll Bar, Mains, and Sides. The format allows the menu to change from night to night as the young restaurant explores what works and what doesn’t. A bright, refreshing rendition of a humble, inarguably Asian salad has held its place among the starters since the restaurant’s opening in October: tart, under ripe papaya shreds tossed with crusty, half-rare slices of grilled hanger steak and crushed peanuts in a wonderful, sweetly spicy lemongrass-caramel dressing ($10). Another, more changeable salad ($13), rings fresh greens with cool white slices of lightly cured Spanish mackerel: a limey, fragrant deconstruction of ceviche. A deliciously creamy, copper-colored soup of pumpkin and sweet potato puree ($8) is warmed with autumnal spices, dotted with crunchy pumpkin seeds, and finished with an intensifying drizzle of reddish pumpkin-seed oil.

Sapa’s handsome, comfortable bar has a good view of the glassed-in kitchen, but the section of the menu earmarked for sharing – and seemingly geared for bar eating – feels like an under inspired addendum, created without the diner in mind. Assorted fried wontons ($10) are wan rather than crisp, their wrappers doughy and their fillings barely identifiable (apples? codfish?). A trio of dipping sauces brings them to life, particularly the concentrated flavor of a superrich Stilton aioli; but that salty, pungent condiment can be enjoyed more readily when it shows up again with excellent battered onion rings ($7). Spare ribs ($12) have an addictively sweet cocoa peanut glaze, but woefully little meat on their bones; contentious groups may want a second order so they can share without fighting. These slips, occasional as they are, don’t stop at the kitchen door: an otherwise keen server allowed us to order a single small bowl of soup that was listed “for the table.” When it showed up, far from shareable, she offered only a blank look – obviously the situation was not covered in the training manual. (The soup was recategorized as a starter on another visit.)

A sushi-style counter in the middle of the restaurant (the “roll bar”) produces thick, ungainly spring rolls. One, packed with suave raw yellowfin tuna ($9), is tasty enough, its unctuous fish buttressed with fatty avocado, but the bland, thick wrapper detracts. A roll of raw wild salmon ($9) and another of tiger shrimp ($8) offer less: they depend for flavor on the standard two dips, a classic piquant one made with fish sauce, another made with chiles and garlic.

Fish entrees show Ms. Yeo at her best. An oily, savory paste made from Chinese-style black fermented soy beans lightly coats plump monkfish filets ($27). The moist, flawlessly cooked fish tastes richly of the sea; the garlic-tinged, faintly earthy bean paste mitigates and complicates the richness. Overfamiliar ahi tuna steak ($30) receives a dose of much-needed excitement from a deeply flavored pile of stewed oxtail meat; dark brown and oniony, it’s an intriguing foil to the keen, ginger-crusted fish.

Pork shoulder ($23), braised until fragile and brick-colored, smells warmly of anise and cinnamon, the fat-seamed meat disintegrating under the fork and on the tongue. A sweetish soy reduction bathes it and its accompaniment of gently biting bok choy. The restaurant touts the dry-aging of a rib-eye steak ($32) that, though deliciously seasoned and admirably well cooked, could be aged further; at 3 weeks old, the steak’s flavor development is excellent but not comprehensive. Flavorful and crisp skin swathes organic chicken that’s ever so slightly too dry ($22); its companion, a fried spring roll of chicken confit, is over rich and unnecessary.

State law requires, I believe, that this sort of stylish establishment be outfitted with colorful cocktails visible on almost every table; Sapa’s include a thin, very sweet mint lemonade spiked with vodka ($9) and an estimable variation on the sidecar that uses a splash of apple liqueur ($9). The varied and surprisingly affordable wine list’s hundred or so bottles are grouped by grape; it also includes sections of “interesting reds” and “interesting whites.” In the latter category, a dry Dr. Konstantin Frank riesling from the Finger Lakes ($27) is unshowy but delicious and well suited to the food.

Sapa’s desserts are well-crafted, but heavy confections like these don’t really suit the elegant economy of the food. Peanut butter gianduja ($8), resembling a big candy bar, tends to overwhelm; its nutty richness is barely countered by a tiny smear of blackcurrant jelly. Caramelized banana tart ($8) achieves a better balance by allowing banana flavor to dominate: sweet, but not oppressively so.

Every restaurant is ultimately a business, but the personal touches of good ones often allow us to forget that fact. At Sapa, those touches are largely omitted: its slick feel and efficient tempo hinder the illusion that it’s anything but a moneymaking venture. The restaurant’s handsome design, and Ms. Yeo’s lighthearted but exact cooking, make it a fine place to socialize. But, seemingly unwilling to break stride in its single-minded march toward success, it withholds the comfortable, flexible niceties that invite return visits.

Sapa, 43 West 24th St., 212-929-1800.