The kua kling Phat Tha Lung at Jitlada may be the spiciest food you can eat in Los Angeles at the moment, a sweet, thick brown curry tossed in a wok with shredded beef, a turmeric-rich endorphin bomb that is traditionally one of the hottest mouthfuls in southern Thailand, which is to say the world. It’s a searing, tongue-scouring, chile-intensive dish that pins your nervous system into the red. Beer won’t counteract the burn. Thai iced tea won’t do a thing. Kua kling laughs at rice. When you order kua kling at Jitlada you are brought a plate of iced raw vegetables to cool down the burn, and the waitress may hover over you for a moment to make sure you haven’t incurred serious soft-tissue damage.

“Is this too hot?” a waitress asked one afternoon when I was at the restaurant with my friend Carl, a composer who used to keep a Thai-language card in his wallet instructing waiters to feed him food spiced for Bangkok natives instead of for the inadequate palates of the farang.

“To tell the truth,” Carl said, “it isn’t quite hot enough. Is this the way it’s supposed to taste?”

She took the plate away and a minute later reappeared with the dish adjusted to southern Thai standards. A few bites later, sweat began to leak out of Carl’s forehead and his gut trembled like a waterbed, but the grin splitting his scarlet, snot-running mug was unmistakable. I reached over and stabbed a forkful for myself. The heat was almost unbearable, and I was surprised to briefly lose muscular control of my knees, but the curry was undeniably better, more balanced in flavor, than it had been in its slightly deracinated version. And then the endorphins kicked in — kua kling, definitely the kua kling.

Jitlada has always been one of the most respected Thai restaurants in Los Angeles, the fanciest place in Thaitown since at least the late 1970s, the local center of the gentle curries and suave vegetable constructions sometimes associated with old-fashioned Thai court cooking. In the 1980s, most local Thais recommended Jitlada when you asked them to name the best restaurant in Hollywood, especially for the grilled giant prawns, the soups and the salads garnished with ornate carved carrots. But by the 1990s, when restaurants serving regional Thai dishes came into play — places specializing in the cosmopolitan street food of Bangkok, the rich cooking of Chiang Mai, intricately spiced Thai-Chinese food and the lean, spare vegetable-intensive cuisine of Isaan — Jitlada seemed staid, a little dull, no matter how splendid the Thai cutlery may have been. When I stopped by the restaurant a couple of years ago, I realized that it was probably the first time I had visited the place in a decade. And when the restaurant was sold last year to southern-Thai chef Suthiporn Sungkamee — “Tui” — and his sister, who answers to the name Jazz, the transition was unremarked, and the menu looked outwardly identical.

But a few months ago, a Chicago blogger who calls himself Erik M. came across Jitlada’s takeout menus stacked in the lobby of a Hollywood hotel and realized that the dense block of Thai text on the back page of the otherwise bilingual document was a list of southern-style dishes that he had mostly never seen before. He visited the restaurant several times in the last days of his trip, methodically making his way through the exotic curries and seafood dishes, getting to know the new owners and developing a working English version of the menu. When he got home, he polished the translation and posted it to a Chicago-area food discussion board, calling Jitlada the most exciting thing going on in the Thai restaurant scene in the U.S. Other bloggers picked up word of Jitlada’s mysterious southern menu. The half-empty restaurant began to fill with Thais, who read about the restaurant’s rejuvenation in local Thai-language newspapers, and with big parties of Internet hounds clutching crib sheets to the hidden dishes. In certain circles, Jitlada was the most famous restaurant nobody had ever heard of, and Tui’s homegrown turmeric, steamed green mussels in spicy lemongrass broth and fried fish “jerky” became open secrets.

Jitlada’s auxiliary menu is almost a thesaurus of southern Thai specialties that you probably haven’t encountered outside a guidebook — things like delicious, foul-smelling yellow curries of fermented bamboo shoots; a Songkhia-style rice salad, khao yam, tossed with toasted coconut, dried shrimp, shredded fresh lemongrass, kaffir lime leaves and a sweet sauce called naam khoei; and whole sea bass shellacked with fresh turmeric, deep fried and showered with crunchy bits of crisp, fried garlic, or plainer fried sea bass glazed with a sweet chile purée.

As you might expect, the southern Thai menu revolves around curries, not just the kua kling but a whirlwind of soupy, pungent and blazing-hot symphonies of thick textures and strange, mephitic fragrances that could have originated almost nowhere else on Earth — wild tea leaves cooked down like creamed spinach with bits of gluey-skinned catfish; beef simmered with pickled buds of cassia (Asian cinnamon) that have the jolt of tropical Red Hots; shrimp cooked with the sour shoots of the tamarind plant; fried soft-shell crab tossed in a spicy, brown gravy with slices of fresh turmeric and heaps of sataw, the fabled stinky bean, which smells like a bad day at the morgue, but tastes like what God probably had in mind when she came up with lima beans.

Is everything great at Jitlada? Of course not, not even on the southern menu. The giant prawns baked in a clay pot tend to be mushy, and the fried pork ribs with garlic are on the leathery side. Non-Thais are apt to be puzzled by the funkiness and the gumbolike consistency of the dried-mudfish curry with kangkong.

But suave housemade fish balls, formed around salted duck-egg yolks, bob in a fresh green curry that may be the gentlest dish on the southern menu. Jazz claims that every few weeks somebody from a well-known Bay Area restaurant picks up a few dozen orders of the kaeng phûung plaa kûng sàp, a pungent, thin curry of various fish organs, minced shrimp and vegetables. The mango salad, a severely spicy take on a traditional papaya salad flavored with coconut water, is wonderful. There iseven special iced coffee whipped to a froth by Jazz and lightened with a secret Thai ingredient that I suspect might be something like Coffee-mate, and the house version of the classic Thai dessert of ripe mango and coconut-scented sticky rice is superb. Jitlada, clearly, is the most exciting new Thai restaurant of the year.

Jitlada Thai Restaurant, 5233½ Sunset Blvd., Hlywd., (323) 667-9809. Open daily, 11 a.m.–10:30 p.m. AE, MC, V. Beer and wine. Difficult lot parking. Takeout. Dinner for two, food only, $22–$36. Recommended dishes: green curry with fish balls; Phat Lung–style beef curry; steamed mussels; kaeng phûung plaa kûng sàp; mango salad; Songkhia-style rice salad.