Some days when he wasn’t overseeing the kitchen at Four Sisters in Merrifield, chef Hoa Lai would find himself a few doors down at Noodles & Company, scanning the chain’s international menu of starchy dishes, which can trace their origins to Italy, Thailand, Japan and the corporate R&D office. The more Lai pondered the place, the more he thought that the concept might work for Vietnamese cuisine.

“I can do this,” Lai recalls thinking. “It’s street food. It’s simple. Why hasn’t anybody done this concept yet?”

Diners enjoy lunch at the Four Sisters Grill, in Arlington. (Kate Patterson/For The Washington Post)

Launched in late April, Four Sisters Grill is not, as the name implies, a counter-service condensation of the more ambitious Mosaic District restaurant with its 100-plus item menu. No, Four Sisters Grill is more of a mashup of the Lai family’s flagship restaurant and Song Que, the Vietnamese deli that the clan operated for more than a decade before closing it in September.

But there’s even an asterisk to that last description, which suggests that the new shop remains in the entire family’s hands. Four Sisters Grill may share a name and a similar clean, colorful, calming ambiance as the landmark Vietnamese restaurant, but the project is solely that of Hoa Lai and his wife, Joyce Alimusa, who are pumping a lot of sweat equity into the place. The couple is always there performing odd jobs, whether ringing up orders or stacking patio furniture at the end of service.

Like the best fast-casual concepts, Four Sisters Grill channels simplicity. The menu consists of only appetizers, banh mi sandwiches, vermicelli bowls and rice dishes. The grilled proteins are often interchangeable: You’ll find some form of grilled pork, beef or chicken on the main dishes. I don’t envy the grill cook’s gig when the Clarendon set descends en masse, their hungry children demanding a quick fix of lemongrass chicken over rice.

Diners enjoy lunch at the Four Sisters Grill, in Arlington. (Kate Patterson/For The Washington Post)

Which leads me directly to perhaps the most pertinent question here: Does this suburban outlet, located just up the street from a Cheesecake Factory, pander to palates not accustomed to the pungency, heat and multi-layered complexity of Vietnamese cooking? Not to sound namby-pamby about this, but I’d say yes — and no. Allow me to explain.

Conceptually, I think Four Sisters Grill may be the most approachable Vietnamese restaurant I’ve ever visited, as safe and inviting as a Chipotle at the end of Main Street, U.S.A., Disneyland. Lai has learned well from his family: He knows how to sell and package his food in ways that don’t make you feel like you’re about to dig into a plate of beef tendon smothered in fish sauce. The banh mi sandwiches come without jalapenos unless you specifically request them; the nuoc mam cham is an elegant, clean and sweet fish dipping sauce, its pungency obvious but not overpowering.

The cold cut combination banh mi at the Four Sisters Grill in Arlington. (Kate Patterson/For The Washington Post)

Personally, a banh mi isn’t a banh mi without jalapeno slivers to provide that final element to balance the competing temperatures and flavors. The cold-cut combination banh mi — with ham, pâté and the emulsified pork roll known as cha lua — comes closest to replicating the Vietnamese street food experience. But only if you add jalapenos. Some of the grilled meat sandwiches can taste too one-dimensional — heavy on the manly grill flavor — without the pepper slices and a hit of nuoc mam cham to provide depth and character.

The vermicelli and rice dishes strike me as flip sides of the same coin. In my crooked world, the coin almost always lands on vermicelli. The noodle bowls allow you to blend flavors better than you can with a rimless plate bulging with jasmine rice. Water pooled at the base of my mouth the moment the grilled lemongrass chicken over vermicelli arrived, its thinly pounded meats so charred and golden that I started popping them before mixing in the rest of the ingredients. The dish only improved after stirring in fish and chili sauces, the latter available on a condiment caddy at the table. The same held true for the grilled shrimp vermicelli, too, although the shellfish was so fresh and delicate the chili heat tended to mute its message.

The grilled lemongrass chicken vermicelli at the Four Sisters Grill in Arlington. (Kate Patterson/For The Washington Post)

The rice dishes, by contrast, spoke in a monotone. The grilled lemongrass beef might capture your attention for a few bites, but after you’ve heard its story for the fourth time, you’re scanning the plate, looking for other voices. The exception to my droning- party-guest theory is the rice plate of grilled pork chops, two chewy and succulent cutlets that release their sweet, caramelized flavors directly onto the grains below. The moistened rice is almost as good as the charred pig.

Appetizers are few, in part because the sweet and acidic papaya salad is practically an entree on its own. But the crispy pork spring rolls, with their preternatural crunch, are a sublime opener when wrapped in fragrant leaves. You also can pair your meal with Vietnamese iced coffee, Thai iced tea or a bottle from the list of craft beers. (Avoid the IPAs, whose bitterness doesn’t align well with Vietnamese cooking.) Four Sisters Grill plans to introduce bubble teas soon, which should satisfy those clamoring for the chewable drinks.

The crispy spring rolls appetizer at the Four Sisters Grill in Arlington. (Kate Patterson/For The Washington Post)

The most impressive thing about Four Sisters Grill may be Lai’s business acumen. He has carved a niche in the local fast- casual marketplace that didn’t previously exist. He tells me the franchise hawks are already circling. And why not? Vietnamese cuisine has long desired to move into the quick-serve mainstream, but Four Sisters Grill may be the first operation slick and tasty enough to make the jump.

Four Sisters Grill

3035 Clarendon Blvd., Arlington.

Hours: Monday-Saturday 11 a.m. to 9 p.m.; Sunday, 11 a.m. to 8 p.m.

Nearest Metro: Clarendon, right around the corner from the restaurant.

Prices: Sandwiches and entrees, $6.25-$13.95.