As ramen continues to gain in popularity in America—moving from major metro areas to secondary cities—the Japanese dish is starting to echo the surprising success of poké over the past few years and the earlier growth of pho.

Ramen shops are springing up across the country, including several multiunit fast-casual operations.

“Ramen is on the brink of starting to expand, sort of like poké did,” says Diana Kelter, analyst with Chicago market-research firm Mintel. “It’s been popular for some time in the big cities and in Japanese restaurants, but we are almost at that time to see it take off.”

Japanese food is far more likely to be eaten out in the U.S. than at home, according to Mintel. Market researcher Datassential also found that ramen has significant appeal to diners under 35, and its menu mentions, while still relatively low, rose 49 percent over the past four years.

Unlike poké and pho, which were relatively unknown to mainland Americans before catching fire, ramen has tremendous name recognition, mostly due to the inexpensive instant-ramen packets that are part and parcel of college dorm rooms.

That awareness is a double-edged sword, however, because high-quality Japanese ramen—the soup, noodles, flavors, and toppings—requires extensive, labor-intensive preparation and is nothing like its cup-of-soup brethren.

“The ramen now becoming popular sticks to its authentic roots,” Kelter says, noting there are almost as many variations of ramen in Japan as there are regions. “So, operationally, you can’t really prepare it without specific knowledge and training.” That also means costs tend to be higher than some other fast-casual cuisines.

Ramen consists of noodles made with wheat flour, salt, water, and alkaline mineral water called kansui; slow-cooked soup that uses meat or vegetable stock and various other ingredients to create clear or cloudy broth; and specific flavoring styles.

Shoyu ramen, for instance, typically has a clear brown chicken or vegetable broth with lots of soy sauce along with curly noodles, bean sprouts, a soft-boiled egg, barbecued meat called chashu, marinated bamboo shoots, green onions, and kelp or other greens.

The first ramen wave in the U.S. was largely at full-service spots, but the dish, despite being labor intensive, is “the quintessential fast-casual” food, says Jake Freed, president of Shiba Ramen, a two-unit Oakland, California, operation.

Much of ramen served in Japan is in a limited-service setting. “You buy a ticket at a vending machine, push a button for the type of ramen, and give the ticket to the person working at the counter,” Freed says. The food arrives in a few minutes.

That is not likely to be the American model for a while, he adds, even though one Shiba Ramen location does offer a kiosk for ordering. “Many customers, especially the new ones, need a lot of hand holding.”

Shiba features several types of traditional ramen, including shoyu, and some of its own creations. It also has vegetarian ramen with a soy milk–based vegetable broth, as well as broth-free ramen called mazemen.

Japanese full-service chain Ippudo brought its tonkotsu, or Hakata, ramen—featuring a pork bone-based broth, hard-centered noodles, and sliced pork belly on top—to America a decade ago. Since then, the company added a quick-service operation, Kuro-Obi, that offers only a chicken broth ramen at three New York restaurants.

At both Ippudo and Kuro-Obi units, “we uphold the standards as though they are in Japan,” says Tomo Yamane, the Japan-based director of corporate strategy for the brands’ parent, Chikaranomoto. He adds that the restaurants “invest heavily” in both quality ingredients and the kitchens’ ability to execute.

A Tokyo-based fast-casual ramen operation, Marukin, has gained a foothold in America by locating two units in Portland, Oregon. It features both Hakata-style and chicken-broth ramen with house-made noodles, all created by Japanese chefs.

David Rademacher, the chain’s U.S. partner, says that unlike full-service Japanese ramen restaurants that offer many menu items beyond the noodle soup, Marukin exclusively serves ramen. “We focus on one thing and want to do it very well,” he says, noting that it includes both traditional and modern varieties, such as vegan versions.

Despite a higher price than most fast-casual menu items (Marukin’s bowls are $11), demand for ramen continues to rise for various reasons: It’s new and exciting, serves as a comfort food, and provides a cultural touchstone. “The impression is that things from Japan have quality and are clean, consistent, and honest,” Rademacher says.

Some other types of American fast-casual chains are also employing ramen in their menus. Minigrow, a four-unit chain operated by Philadelphia-based fast casual Honeygrow, uses mazemen noodles and techniques in its bowls.

Unlike Honeygrow, which stir-fries egg noodles, Minigrow’s thick wheat or spinach mazemen noodles are cooked in water and tossed “immediately while hot in a mixing bowl with a flavorful sauce,” vegetable stock, and garlic oil, says David Katz, the company’s culinary director. The noodles are transferred to a bowl and guests can choose toppings that include proteins, vegetables, and garnishes ranging from dashi poached salmon to pickled chilies.

Some of the sauces, like red miso and shiso basil pesto, have some Japanese links, while others, including black pepper tahini, do not. “We aren’t shooting to be anything like a traditional ramen shop,” Katz says. “We are trying to be more versatile.”