The US has often been described as a "melting pot" -- and though some now consider the metaphor outdated, it still holds true when it comes to food. Immigrants from around the world have for centuries adapted their traditional dishes to incorporate native ingredients or to accommodate other tastes on US soil.

One of the most popular remixes is the category of Asian fusion. These intercultural collaborations tell a unique story, from adapting a plate of chow mein for European palates in the early 20th century to combining Korean barbecue with Mexican tacos nearly 100 years later. Each of these creations marks a distinct era in US immigration -- while some are fading, others are now taking off. Here's a look at how some of them came about.

Korean-Mexican cuisine brings L.A. together

The Kogi BBQ taco truck isn't simply fusion, as chef Roy Choi describes it. It is a "psychedelic intersection" of cultures found in the specific 3-mile radius of Los Angeles' Koreatown, making it distinctly "Los Angeles food" for, and by, American children of immigrants.

Choi told CNN his food is an amalgamation of traditional flavors found in this region, including culinary traditions from Korea, Central America, certain parts of Mexico and Bangladesh. He remembers aunties and mothers of neighbors and friends, cooking and selling their food on street corners.

He said the Kogi BBQ truck "channeled all the history and ancestry of street food -- the loncheras and the taqueiros -- we came from that culture."

Choi said the Kogi short rib taco was inspired by a drunken night outside a club eating tacos when his business partner wondered if he could put Korean barbecue in the tortilla instead of carne asada. Today, customers will find their short rib taco topped with cilantro, onion, lime and a relish salad that's reminiscent of an appetizer served before Korean barbecue meals. Choi also makes a hybrid salsa verde using Korean chiles, dried Mexican chiles and California produce.

Choi said his food speaks to a generation of children who were not raised in their "mother" countries.

"We grew up hopscotching between two different cultures and languages. But we still got to figure out how to be American. And that whole kind of divide and purgatory, between identity, is what our food is," Choi said.

Whether he's making slippery shrimp, shaking beef or kogi tacos, Choi said his food is a mutation of original dishes that do not look like the names they are given. Over time, this evolution turns into its own type of food, he said, in the same way the Hawaiian plate has become its own cuisine, or the way Italian American food was established.

For now, Choi said this is a new culture that we're witnessing: "When people (got) into this taco, it felt for the first time, like L.A. had all come together in one bite."

Vietnamese refugees transform Louisianan food

Chef Nini Nguyen said Viet-Cajun food arrived when a large group of Vietnamese refugees came to Louisiana after the Vietnam War, but this phenomenon didn't truly take off until after Hurricane Katrina. These major events shook up entire communities, transforming the way they eat.

After the Vietnam War, Nguyen's parents ended up in New Orleans, where many Vietnamese refugees were largely housed together, sponsored by the Catholic Church.

New Orleans seemed immediately familiar to this new immigrant community. The city had also experienced French colonialism. Its people were used to a hot and humid climate, they were familiar with the seafood industry, they also drank coffee with milk, they had their own version of beignets, and their po' boy bread was similar to Vietnam's banh mi bread.

"I only eat po' boys with Vietnamese bread," Nguyen said. The light, airy, crumbly texture of Vietnamese bread comes from baking the dough the same day that it's made, she said, rather than letting it ferment the way denser, French baguettes are made. Nguyen said that texture and taste are more suited to hot and humid weather.

But Nguyen points out that for decades, her family and other Vietnamese immigrants learned to make authentic local Creole cuisine, carefully following traditional methods and ingredients. And while she saw a Vietnamese-owned corner store adapt local recipes by adding a little Vietnamese fish sauce or chicken bouillon powder, the adjustments were far from extreme.

"It is a delicate place," she said. "We... for a long time, felt like we needed to accommodate to their palate, because this is what they want. This is how they like it. And this is, you know, being respectful to that cuisine at the same time."

But when Hurricane Katrina hit in 2005, many New Orleanians migrated to Houston, where Nguyen said they felt free to try culinary experimentation.

Soon, crawfish boils came with buttery, aromatic sauces full of garlic, lemongrass, Thai basil and tamarind powder. Banh mi po' boys were filled with dripping, saucy, fried shrimp with pickles, cucumber and cilantro. Meanwhile, Vietnamese coffee in the US had become synonymous with New Orleans' Café du Monde, with the café's iconic orange-yellow tin cans holding bunches of chopsticks in Vietnamese restaurants.

While New Orleans city cuisine is more Creole, Nguyen said rural Louisiana cuisine is considered Cajun.

"We just call it Viet Cajun, but it's really Louisiana food," Nguyen said of this Vietnamese-influenced cuisine. "We're finally in a place where one -- we feel like we can do these things, which I think is very beautiful, and two -- that people want to eat these kinds of things. And so, I think it's a very exciting time for Vietnamese people to be able to be themselves, wherever they are."

As some people have migrated back from Texas to Louisiana, "Viet Cajun" food has become more popular. Nguyen is creating a cookbook, where she'll throw in her own fusion recipes, including blackened catfish with curry and lemongrass seasonings.

Chino-Latino meals can still be found in New York

Jose Tso made it clear: he doesn't feel Chinese-Cuban cuisine is "fusion." Tso said it simply means cooking and serving Spanish-style dishes, alongside Cantonese-style Chinese food, side by side.

"They just complement each other. For example, like Spanish cooking is a lot of times heavily seasoned. And concentrated on broiled, grilled or fried. And Cantonese-style Chinese food is not that much fried, but sauteed and cooked or steamed with water in the wok. So, if you have an oily mouth, and you have some nicely freshly cooked, hot, but not greasy Chinese vegetables, it just complements each other," Tso said.

Tso and his nephews are the current generation of owners of the Flor de Mayo restaurant, which has three locations in New York City. The name, Tso said, is the Spanish translation of "Mayflower," to represent the spirit of pilgrims who came by sea, looking for a better future.

Tso said Phillip Chu and William Cho, the founders of the first Flor de Mayo restaurant, came to New York from Guangzhou (previously Canton) via Peru. When they arrived in the US in the late '60s and early '70s, there was already a bustling industry of several hundred Chinese-Latin restaurants, run by Chinese immigrants who had first immigrated to Cuba, but then fled to the US in the 1950s during the Cuban Revolution.

Chu and Cho worked for several of these restaurants, ultimately working at one called Asia Star. When the owner retired, they took over and transformed it into Flor de Mayo.

Today, Tso said Flor de Mayo still makes Cuban dishes, including steak tenderloin with sauteed onions, ground or chopped beef in sauce, sauteed beef, chicken liver, rice and beans, plantains and avocados. At one location, they added Peruvian rotisserie chicken. The Chinese food serve includes steamed vegetables, pork chop, fried rice, spare ribs, wontons and lo mein.

While the Spanish-style cuisine requires more pre-seasoning before food is fried, the Chinese food is typically seasoned while being sauteed in a wok. Over time, Flor de Mayo has excelled in preparing the two cuisines in one kitchen.

"Our Spanish food and our Chinese food is interchangeable in the way of how to cook it... Some Spanish dishes we can also cook in the wok," Tso said.

But the tradition is fading, as the largest waves of Chinese immigrants who came to the US via South and Central America arrived mainly in the 20th century. Tso said those who still come through that route today have more education, with more opportunities for higher-skilled jobs.

Doing the difficult work of running a restaurant "will give you stability like a steady income, but it won't make you rich. And in order to achieve this so-called steady income, you spend a lot of time...nowadays, the next generation do not want this kind of lifestyle," Tso said.

By Tso's estimates, there are currently fewer than 10 Chinese-Latin restaurants left in Manhattan.

A chow mein sandwich becomes a tradition in a Massachusetts town

Regina Mark's Mee Sum restaurant is not where the chow mein sandwich was invented, but it is one of the modern bastions of this odd tradition that has captured the attention of foodie Instagrammers while serving as a reminder of the industry Fall River, Massachusetts, once had.

Mark's in-laws' family emigrated from Canton, now known as Guangzhou, in the first half of the 20th century. She said they came by way of Arkansas and Rhode Island to Fall River, which was then a buzzing textile town with European immigrants working in factories and mills.

Mark said Europeans were used to having garlic bread with their spaghetti and wanted bread with each meal. Local Chinese restaurants were already serving chow mein with a few slices of bread, so a person could soak up the brown gravy and push around the noodles.

"And then one day, this restaurant, they ran out of the sliced bread. The owner says, 'the only thing I have is the hamburger bun. Would you mind?' So, he gave them a couple of buns to take home, and... the customer liked it. He said 'hey, you know I made a chow mein sandwich out of it, and you should start that,'" Mark said.

Today, one can order this dish on a plate, where brown gravy-covered crispy noodles flow with reckless abandon between two halves of a hamburger bun. Or, if ordered via takeout, it can be eaten by hand like a burger out of wax paper, and when slightly cooled, the brown gravy congeals and helps the noodles and buns maintain structure.

In the 1940s, Mark said Mark Restaurant sat on the second floor above a movie theater in downtown Fall River, where cinemagoers could go upstairs after a movie and get a chow mein sandwich, soda and dessert for 50 cents. The restaurant also sold fish and chips, fries, and coleslaw. But "teaching" people how to eat fried rice and egg rolls was a challenge.

"One week, at that time, we sell maybe a dozen egg rolls. When my in-laws started it on the menu, people don't even know what it is. What is it? And they started learning how to eat it. And now we sell hundreds and hundreds," Mark said.

The original Mark Restaurant is now gone, but her in-laws had also opened Mee Sum Restaurant in 1950, which is now run by the next generation of Marks. Their chow mein sandwich and their fried rice carries a darker color than the way other Chinese restaurants make it, Mark said. That's because she adds a caramel coloring to evoke the feeling of a richer, beef dish.

"People eat with their eyes before they taste it. If they don't care for (the appearance), they don't want to eat it," she said. "Food always brings people happiness. You can, no matter what time it is, you entertain people with food."

Mark reflected on the rough life the first generation of Marks experienced, arriving in the US by boat, establishing themselves in a town where other Asian immigrant families were initially hostile toward new restaurant competition, and having barely enough money to heat their home.

Today, her family's restaurant thrives as a key part of the Fall River community. She's not sure that there's anyone in the younger generation willing to take over the business. But for now, she and her family continue to feed and entertain New Englanders and visitors who come from afar to try their chow mein sandwich.