Ask Nat Ongsangkoon or Dia Khanthongthip how American-style Thai food differs from the dishes they eat in their native Bangkok, and they don't hesitate. The couple, in fact, uses the exact same word.

"Sweet," says Ongsangkoon, barely waiting for me to finish the question.

"It's sweet," echoes Khanthongthip. "It's not. . ." She trails off, searching either for the right words or the most diplomatic ones.

"It's not flavorful," her husband completes the sentence, losing all diplomacy.

"Thai people like herbs, like spice," Khanthongthip continues the thought. “I think the food that I eat, some Americans cannot eat. But right now, I think more Americans can eat the thing that I eat now, because everything has changed. Everyone wants to try the real [Thai food]."

Authentic Thai food is what Khanthongthip and Ongsangkoon plan to offer at Soi 38, their forthcoming restaurant located in a West End space that some Washingtonians will recall fondly: The couple's spot at 21st and L streets occupies a chunk of real estate that used to house Galileo, where chef Roberto Donna once performed a similar act of kindness for District diners. He introduced many to the real flavors of Piedmont, permanently placing a wedge between red-sauce-centric Italian-American cooking and regional Italian cuisines.

Opening April 15, the 142-seat Soi 38 is named after an avenue in Bangkok, Sukhumvit Soi 38, where dozens of vendors set up carts and rickety little tables for strolling pedestrians to sit down and have a bite of Thai street food during the evening (and well into the morning). "Every time we go back" to Bangkok, says Khanthongthip, "we always go there."

The strip is sort of like Bangkok's equivalent of Adams Morgan: a boisterous place where young adults go for a nosh after the bars clear out at 2 a.m. "When I was in college, when the bars closed and we needed something to eat," says Ongsangkoon, "we'd go there.” And stay there until 4 or 5 a.m., he adds.

The D.C. version of Soi 38 will serve dishes as authentic as the stuff in Bangkok, the couple promises, mixing street food with plates that reflect the northern Thai background of chef Mitchai "Mit" Pankham. Whatever dish he prepares, the chef plans to pull no punches: the fish sauce, the chili heat, the vinegar-heavy sauces, all of it will be available at full Thai strength.

A former chef in Thailand, Pankham has been working with Khanthongthip and Ongsangkoon at their first restaurant, the nearby Thai Place, which the couple has run for a decade now. The owners will be the first to tell you Thai Place is a typical Thai-American operation, like so many around the District (until, that is, Johnny Monis introduced us to northeastern Thai via Little Serow).

Names of certain dishes may be similar at both places, but Khanthongthip says the tastes will be far different. Soi 38 will prepare them Thai-style — in a space designed, as architect Francisco Beltran says, "to keep it very simple, with a mixture of the grit and elegance." (Those mythical creatures that hover over the room? They were created by Baltimore street artist, Gaia, who also brought his work indoors for this project, in a symbiotic connection between dining room and kitchen.)

Most Thai restaurants serve larb gai, that standard-issue minced chicken salad, prepared either as an appetizer or entree. Soi 38 will offer a larb tod instead: an altogether different preparation, in which the chicken is chopped into larger pieces and deep fried, creating a crunchy exterior but lush interior. (See photo above.)

The menu (see below) will be divided into sections such as rolls, small bowl/hot pot, yum, main course, curries and noodles/rice. Among the atypical Thai dishes (at least in the District) are kor moo yang, a grilled pork neck appetizer with lime and chili sauce; tom yum kradook moo, a spicy lemongrass soup with bone-in spare ribs and chili; kana moo krob, a flash-fried pork belly with Chinese broccoli, garlic and oyster sauce; and khao pad sapparod, pineapple-fried rice with shrimp, cashews and carrots, served in a pineapple shell. Expect an expansive dessert menu, too, with such finishes as kluay roti with fresh banana, fried roti and condensed milk.

The cocktail program comes courtesy of J.P. Caceres, the embattled bartender who is whipping up drinks with classic Thai flavors, whether lemongrass, ginger or kaffir lime leaves. Among the planned libations are a Thai Manhattan, spiked Thai coffee and teapots of Thai-inspired punches. Tap handles will feature not only a house-made Singapore Sling, but also Singha, the Thai beer usually found in bottles.

"We’ve been doing business for 10 years," Ongsangkoon says. "Our dream is to sell what we eat when we go back to Thailand.”

Soi 38, 2101 L. St. NW, opens on April 15. Phone: 202-558-9215.

Dinner Menu: