He was still dressed in his crisp boardroom suit, the silver mane neatly coiffed, the designer glasses just right, a mail-order bottle of cult Napa cab open ("it's my ex-wife's favorite. Would you like a taste?") and a feast before him that pinged the greatest hits of the Mustard Greens canon.

There was an aromatic nest of toasty garlic noodles, a steamer basket of handmade pork dumplings, a vivid-green mound of heat-blistered string beans with bits of pickled cabbage, a crispy fan of butterflied trout glossed with dark Hunan sauce, and, yes, the obligatory indulgence of Mustard Greens' General's chicken.

The only thing missing, it seemed, was another guest. And as it became apparent that status wouldn't change while the fellow blithely nibbled at his lavish banquet, occasionally pausing to chat with favored servers and cashmere-clad acquaintances across the room, I found the scene both poignant and reassuring.

Sometimes in life, as in dumplings, the comfort and consistency of a restaurant relationship can outlive many personal ones. After 23 years of understated Cantonese elegance on this quiet Second Street stretch of Queen Village, I suspect chef-owner Bon Siu has forged more of these enduring bonds than most.

I've heard from many of his devoted customers over the years and, until now, never stopped in for a proper review. I've understandably been distracted by Chinese kitchens with more creativity (Susanna Foo), more unvarnished authenticity (my many Chinatown favorites), and the lip-numbing pyrotechnics of Han Dynasty and the Sichuan revolution that followed. There are other thrilling regional Chinese menus in town, too.

But after several recent meals at this pleasant minimalist haven, with its soothing green walls, dark wood floors, and sleek glass facade, I've come to appreciate Mustard Greens not simply for its understandable longevity as a neighborhood favorite. I've also grown to admire its commitment to high-quality ingredients at very fair prices (all sub-$20 an entrée) and a decidedly light touch with sauces that highlight freshness in a manner that's true to the chef's Guangzhou roots.

Siu will confess he likes simple food. But don't confuse that aesthetic with lack of flavor. One of his favorites, and mine, is the shrimp with shiitakes, which look like every other sautéed shrimp dish with snow peas I've had. Except that the added snap of slivered mushrooms lends the clear sauce an unexpected earthy layer of umami that amps up the sweetness of those plump butterflied shrimp.

The wonton soup is also clear, not the typical golden (usually thanks to food coloring), but it is restorative around thin-skinned wontons and crunchy threads of enoki mushrooms. The even more austere Cantonese soup is a soft-spoken texture play, the tofu curds soft against tender crumbled chicken and velvety plumes of baby spinach. The garlic noodles look exceedingly plain. But each thread is infused with a toasty garlic swagger that isn't oily.

Siu does not shy away from spice. Some of my favorite dishes here bring a confident heat, but it never overwhelms. The firecracker pork brings tender strips of loin glazed in sherry sauce that rings with ginger and chile spice. Lollipop lamb chops spark with a rub of Chinese herbs. The unusual curried beef soup brings a flavorful broth tinted yellow with aromatic Singapore-style spice that tickles the nose as you slurp translucent cellophane noodles tangled with crumbles of beef.

A measured hand with chilies also lends balance and perk to the menu's sweeter sauces, from the dark glaze covering the BBQ shrimp (sherried hoisin with peppers), or the Sichuan hot bean paste and ginger at the base of a complex black Hunan sauce that gives the delicacy of a crispy whole rainbow trout its magnetic mystery powers (a steal at $18).

A little extra heat is also what distinguishes Siu's "General's chicken" from most. It's not my favorite dish. And Siu concedes he made up his version from scratch by request of his longtime clientele - almost all of them well-to-do non-Asians over 50 who appear to have shuttled over from Society Hill Towers: "I never heard of General's chicken in China, but it's my best-seller!"

I don't blame Siu for catering to the faithful who have sustained him all these years. Though, among the other popular clichés I could also do without are the greasy spring rolls, the so-so mooshoo pork (our dry pancakes fell apart), the fried squid (too chewy), and any of the BBQ pork dishes, which are OK, but lack the depth of Chinatown's better versions.

One odd relic of antiquated Cantonese cooking I find myself obsessing over, though, is the special duck - first fried, then stewed in aromatic five-spice broth, then deboned, battered, and deep-fried whole. Served beneath a garlicky brown sauce, it's both bizarrely ugly and irresistible, each morsel at once crunchy, ducky, and clad with gravy-soaked crust.

What Mustard Greens has most definitely mastered, though, and not surprisingly, are the sautéed greens, from the peppery mustard greens to the garlicky string beans and more delicate, nutty-sweet pea leaves. Eggplant is given a similarly satisfying touch, whether stuffed like a sandwich with ground pork and lightly crisped inside batter, or as purple-skinned batons tossed in a spicy dark-luster garlic and hot bean sauce, whose light vinegar tang heightens the eggplant's luscious softness.

Seafood is also well-treated. The five-spice crisped softshells are legendary when fresh in season. Huge lumps of sweet crab studded a textbook fried rice, its tiny veggies singed with the smoky breath of a hot wok. Even a completely inauthentic fish for Chinese cooking - salmon - is lovely when carefully steamed with black bean sauce. Salmon is still a big seller here. And a grateful Siu aims to please.

But I look at the mostly silver-haired clientele dishing-out family secrets here as if kvetching in their own living rooms ("my ungrateful children are more loyal to their mother's father than they are to me!" barked a man behind us) and wonder how long Mustard Greens can go on without evolving - at least a little.

Siu talks of new inspirations from a recent trip to his homeland. I'm intrigued by some steamed seafood delicacies of his native South China, which would be a fascinating counterpoint in subtlety to the oily Sichuan flames now raging across Philly.

Or perhaps Siu will stop wasting his liquor license on forgettable generic wines and beers, and discover what fresh energy a serious craft beer and fun cocktail program can generate. Mustard Greens has occupied such a treasured place in the lives of its longtime customers, it deserves an opportunity to be appreciated by a sustainable new audience, too.

MUSTARD GREENS (TWO BELLS OUT OF FOUR)

622 S. Second  St., 215-627-0833; mustardgreensphilly.com

Chef-owner Bon Siu's elegantly simple "contemporary" take on Chinese cuisine has remained a Queen Village favorite for 23 years, and for good reason. His affordable menu is targeted toward a faithful, largely non-Asian, audience, but toes a delicate line between mainstream appeal and an authentic touch that lends superbly fresh, high-quality ingredients, from plump shrimp to lamb chops, a light-handed simplicity true to his Southern Chinese roots. Consistency is key to Mustard Greens' success, but, with more Chinese competition than ever, a reluctance to subtle evolution (both on the menu and limited drink list) risks stifling its ability to cultivate a sustainable audience.

MENU HIGHLIGHTS Hot and spicy panfried dumplings; stuffed eggplant with black bean sauce; wonton soup; curried beef soup; Cantonese soup; sautéed greens (mustard greens, pea leaves, green beans); eggplant with garlic sauce; lamb chops; firecracker pork; chef's duck; shrimp (barbecue-style, shiitakes); Hunan-style rainbow trout; steamed salmon with black bean sauce; crab fried rice; garlic noodles.

DRINKS There is a small list of generic wines and mass-market beers, with Tsingtao the best choice for this menu. Meanwhile, Mustard Greens wastes the possibilities for growing a clientele with better use of its beer and spirits program.

WEEKEND NOISE The minimalist space can be noisy, but the mostly mature clientele rarely bumps above 84 decibels. (Ideal is 75 decibels or less.)

IF YOU GO Dinner Sunday through Thursday, 5-10 p.m.; Friday and Saturday, until 11 p.m.

ENTRÉES $8-$18 (lobster special higher, at market price).

All major cards.

Reservations suggested.

Not wheelchair accessible (dining room is accessible, but bathroom is not).

Street parking only.

215-854-2682

@CraigLaBan

www.philly.com/craiglaban