The doubt creeps in the moment you arrive at the painted-red storefront along University Avenue in St. Paul's Frogtown neighborhood, near the other Hmong shops. Maybe it's the nondescript wording of the name, Thai Café; the way a red flickering "Open" sign snares you; or the often empty, sparsely decorated interior that makes you think twice.

Enter regardless, and you wonder how a restaurant can exist in a space no bigger than a Subway joint, the walls sporadically littered with laminated food photos, an antique lamp in the corner and black vinyl chairs huddled around four tables. Then you notice a woman tending to a stove behind the counter, in a neat kitchen bigger than the dining room — arms askew, brows furrowed, serving a group of students leaning over their bowls of Thai boat noodle soup, slurping wordlessly.

You may be in the right place after all.

I never had the chance to try those boat noodle soups. Not because I was thrown off by one of the ingredients — cow blood stock — but because almost every dish I've had at Thai Café had left me in thrall and convinced me to save those noodles for the next time.

The real reason is the sour pork ribs, the restaurant's signature dish ($15.99). I don't stop eating until the stubby bones are clean and leave me feeling guilty, like the kid who indulged in sweets before dinner.

They're fermented over four days to achieve peak funk in a "secret" sauce, then stirred in oil with kaffir lime leaves, garlic cloves and dry-roasted chiles. By this point, the caramelization lingers but the meat has surrendered, commingling in a tender bite that is savory, spicy and intensely tannic.

"No shortcuts," Lao Vue tells me.

Five years ago, Vue and his wife, Lynn Her, left their corporate jobs and bought the restaurant from the original owner, Yuwadee Poophakapanart, who is from Bangkok. Her executes the original recipes in her exacting standards, sourcing local and staying true to the dishes' origins.

Featherback fish, a thin, tender breed native to Southeast Asia, is ground by hand and formed into puck-sized patties ($6.99), along with julienned long green beans, kaffir lime leaves, coriander root, celery and egg. The patties are fried twice — once to retain its shape, then again before serving. You can taste each ingredient even though the patties have been fried till they crackle and a dark crust forms around the edges. You dip a bite with a lilting relish made with cucumber and red-onion vinegar, and the whole affair will haunt you.

It lives on the menu under a reductive name, Fish Cake, just above cream cheese wontons, and its placement doesn't do it justice. I feel the same about Chinese Broccoli Stir Fry ($11.99), which tastes much better than it sounds and reveals more than its origin suggests. Mostly because it comes with little nubs of pork belly, deep-fried until their fat stiffens but remains gelatinous and as addictive as soft jerky.

And I feel the same about the Khao Mun Kai, or chicken rice ($11.99) — a dish brought by the Hainanese to Thailand — because it is, in fact, chicken over rice, but so much more.

The rice has been cooked in stock just until each morsel becomes dewy with fat, and the chicken shivers apart. You can (gladly) subsist on this dish alone for lunch or an early dinner — Thai Café closes at 7 — but that means you would miss out on everything else.

The curries, for one. My favorite among them is the green curry ($10.99), a soupier variety which either resembles Monet's "Water Lilies" or algae, depending on your perspective. What isn't debatable is the depth of its broth, redolent of lemongrass and basil. The pieces of chicken within are velvety, but all I could think about was how I could drink the curry without making a scene.

Where many other Thai restaurants in the Twin Cities tend to push maximalism (sweetness, spice, among others), Her reins in. The curry is not just emblematic of her approach, but of many other dishes, too.

Rad Na, or wide rice noodles in gravy, is not gloopy like it tends to be in other restaurants; here, the sauce is soupier, thickened with just enough cornstarch so it clings onto the al dente noodles ($11.99). Likewise, Pad See Ew, the stir-fried version, goes easy on the sauce so its sweetness quietly — and rightfully — cedes to the noodles, which taste of wok and char ($10.99).

Though the fried fish laab ($14.99) is firmer than anticipated, and though it doesn't have the pomp of the one at Khâluna, it still is a thrilling dish, mostly because the thin curry sauce teeters between floral and spice, and it's appealing enough to moisten each bite. Order this if you know your way around whole fish.

But know that the authenticity of Thai Café shouldn't preclude you from ordering the classics. The laab salads are properly vibrant, and all of the stir-fries hold their own. Pad Krapow, or basil stir-fry ($11.99), is especially a marvel because it's likely flash-fried in enough oil until each morsel of ground pork caramelizes, like Cocoa Krispies briefly soaked in milk. On top is a fried egg, cooked the Thai way, with edges lifted and cradling the soft yolk, reminiscent of a UFO. You will be asked about spice level. Choose (at least) medium and you'll garner respect from Vue.

He's a hospitable owner, larger than life. His nickname, Mr. 555, is the Thai equivalent of "LOL." In this language, five is pronounced "haa."

At first I thought he was in character, pulling a fast one on us when I asked him to recommend an epilogue of a dish. "Cashew chicken."

He wasn't. The satiny strips of chicken; the controlled chaos of sweet and heat; the Riesling-like dry finish ($11.99). It's a technical marvel even for a basic dish — the least to expect from what surely is the finest Thai restaurant in the Twin Cities.

Thai Café

371 W. University Av., St. Paul, 651-225-8231, thaicafemn.com. Open daily 11 a.m.-7 p.m.