Restaurants focused on one ingredient are becoming more and more popular.

McDonald’s is testing out a Quarter Pounder with fresh beef. Vegan Beyond Burgers have hit the menu at TGI Friday’s. Is fast and fast casual food making a move toward selling healthier options? You might look to Norway’s largest producer of salmon for confirmation of the trend: It’s planning to open to a salmon-only fast food chain in China.

According to a report from the Financial Times, Marine Harvest already operates five restaurants under the chain Supreme Salmon in Tawain, but hopes to open at least 2,000 more locations in China. The restaurant serves a whole range of salmon-centric dishes, including salmon gyoza, salmon risotto, and salmon fried rice. Marine Harvest hopes that by opening the restaurants, China’s demand for farmed fish will go up.

In the states, the closest that we have to a restaurant that is centered on just one ingredient would be the growing number of places that serve all-avocado dishes. At the moment, most of them are located in New York City, but at least one, called Avocaderia, hopes to expand to locations across the country. Still, this is more evidence that restaurants groups are looking for opportunities to capitalize on the healthy eating trend, and perhaps even moving farther away from meat-based fast food options.

Even McDonald’s is testing a vegan burger, while the Impossible burger venture—the soy based burger which looks like it bleeds—has raised $75 million in funding, and is already showing up at places like Fatburger. Vegan burgers are also a—perhaps still evolving—answer to the question of whether or not more restaurants will adopt environmentally sustainable options.

Fish might not be popular enough in America yet to warrant an entire fast food joint dedicated to it—it’s not exactly what Americans would consider a dish for casual eating—but the push to create more health-conscious food options is clearly happening on a global scale.