In our car-dependent landscape, no two words send a spasm of fear through a restaurateur's heart faster than road construction.

Due to the Central Corridor light-rail construction, navigating certain stretches of University Avenue in St. Paul and Minneapolis has quickly become world-class "Excedrin moment" territory. If the orange-cone landscape is an anywhere-but-here turnoff for drivers, imagine what the business owners must be thinking.

My pea-sized brain often turns to On Khumchaya. The On of On's Kitchen probably couldn't have picked a more challenging time to launch her restaurant, bravely situated a half-block west of the obstacle course known as the intersection of Snelling and University.

The Twin Cities area is blessed with plenty of Thai restaurants, but few possess the distinctive personality and heartfelt warmth of On's Kitchen.

By the way, that name is right on the money: Walk in the door and you'll find Khumchaya laboring away in her galley-style kitchen with the concentration of a diamond cutter. Only the very clueless would sit in her modest dining room and not be aware of her presence, whether it's the sounds of woks clanging in the open work space or the chef herself, gliding from stove to table, a glorious dish in her hands and an ever-present woven cap on her head.

"Here, I show you how to make," she said as we hesitated in front of her pretty plate of meing-kum, grabbing a dark green lettuce leaf and quickly spooning bits of dried shrimp, lime, peanuts, red onion and a rock 'em-sock 'em Thai chile and dressing it with a thick, dark, lightly sugary sauce. "Now eat in one bite," she instructed, and we did. A dizzying medley of flavors and textures popped in my mouth. The rest of the plate disappeared, fast.

Another image I can't forget: Khumchaya, the expression on her face one of unabashed pride, presenting a magnificent whole steamed tilapia to our table, the glistening, silver-scaled fish scattered with thin-sliced lemons, greens and garlic. She returned a few moments later with a bowl of golden broth, its garlic-lemon-pepper steam snaking into my nose. "You spoon soup over fish like this," she said, offering a quick tutorial before we dug in, the white flesh tender and moist, the broth's gently sour bite laying a slow-build heat in the back of my throat.

It's a 'good heat'

Honestly, traffic hassles fall by the wayside when the food is this good. I can't imagine not ordering huh-mok, a kind of fish custard -- steamed tilapia -- singing with lemongrass grace notes and served inside a banana leaf shell over a bed of slow-braised cabbage. Why can't my Scandinavian ancestors' idea of comfort food possess a similar vitality?

Ditto the fantastic, black olive-size pork sausages, which boast a willfully garlicky kick. Khumchaya fries them until their snappy skin takes on a caramelized glow, then serves them with a do-it-yourself wrap of cabbage, cucumbers, thinly sliced fresh ginger and a few sinister red Thai chiles.

Other don't-miss dishes: shaved pork neck, rich and slightly fatty, stir-fried with chiles and garlic and dressed with cool mint and Thai basil. The green and red curry dishes are a delight, with subtle flavor layers and a spicy heat that sneaks up rather than immediately overwhelming. "It's a good heat," said my friend, who didn't realize we were eating on Khumchaya's pilot-light spice level. She can really crank up the heat. In a "good" way.

My already marginal table manners evaporated the moment that a whole fried king crab materialized, the sweet, succulent meat finished with bits of scrambled egg and a deeply aromatic yellow curry sauce. Where is one of those tacky plastic lobster bibs when you need one? The bliss continued when a plate of crispy soft-shell crabs arrived, perfectly fried, delicately seasoned, utterly delicious. And far less messy.

The menu's overwhelming, 100-plus roster spans the continuum of home-style and restaurant-style cooking, with doses of street-food fare tossed in, but Khumchaya goes to great pains to ensure individuality among that vast (maybe too enormous) assortment. Still, the initial reaction of some diners might be to fall back on familiar Thai-American favorites. That's OK, because Khumchaya treats them with respect. There's a fine pad Thai. I loved the slim, crispy-edged chicken satays, with their rough-and-tumble peanut sauce. The hot-sour soup is a thing of beauty, and a papaya salad was brightly refreshing. Spring rolls are packed with fresh, herb-y goodness.

Plus-size, salt-crusted shrimp had a notably appealing snap, as did the delicate shrimp dumplings, garnished with crunchy bits of dried shrimp and tons of fragrant cilantro. Even most of the pro forma options I sampled (chicken in a light mushroom sauce, jazzed with long strips of thin-cut fresh ginger) were a treat, their leftovers more than worthy of a takeout carton. Other words of advice: Skip dessert, and keep your expectations of the friendly service staff to a minimum.

Not just a hole in the wall

The seemingly tireless Khumchaya embodies the wisdom of an open-arms immigration policy. She's been in Minnesota for 20 years, working at a downtown Minneapolis hotel -- and then briefly at her sister's nearby Bangkok Thai Deli -- before nabbing the former BonXai on Dec. 1.

On's Kitchen opened the next day, and Khumchaya's enterprise, hard work and know-how have been enriching life in this particular corner of the Wonder Bread State ever since.

I wasn't shocked to learn that the building, a variation on the don't-blink-or-you'll-miss-it school of low-budget hospitality design, was a former Best Steak House. But it would be a mistake to underestimate its cookie-cutter looks. On Khumchaya makes her place a one-of-a-kind find.

Rick Nelson • 612-673-4757