Many people in America love Chinese food, but David R Chan is perhaps in a league of his own.
Mr Chan, a 72-year-old former tax lawyer based in Los Angeles, claims to have dined at nearly 8,000 Chinese restaurants across the US and counting. Each is archived in a spreadsheet that he has maintained for four decades, along with thousands of restaurant business cards and menus.
If you visit one Chinese restaurant per day, it would take more than 20 years to reach his current count - 7,812 restaurants.
From pineapple buns and pork belly to chicken feet and tea-smoked duck, the Chinese restaurant "collector" documents his food conquests almost daily on his social media accounts.
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Though his food journey started as part of a search for his identity as a Chinese American, Mr Chan said, over the years it has become itself a chronicle of the rise of Chinese food and changing dynamics of Chinese culture in America.
Mr Chan isn't a typical Chinese food critic, and he insists he isn't even a foodie. He has no aptitude for using chopsticks, he said, has given up tea to avoid caffeine and adheres to a low-sugar, low-cholesterol diet.
But that has not stopped him.
A 'collection' of Chinese foods
Though he is the descendant of grandparents who immigrated to California from China's Guangdong province, Mr Chan did not eat Chinese food as a child. And when he first tried Chinese fare, he was not impressed at all.
"The food was not sophisticated," Mr Chan recalled of his first Chinese meals in the 1950s. "We would go to banquets, I'd eat soy sauce on rice, and nothing else."
Chinese food was first cooked in the US by Chinese immigrants who came dreaming of wealth during the California Gold Rush in the mid 19th Century. In 1849, the first documented Chinese restaurant, Canton Restaurant, opened its door in San Francisco.
The early Chinese immigrants in the US were mostly from Toisan, a rural Cantonese county in southern China. The coastal community had a tradition of sailing abroad but was experiencing bloody ethnic conflict and economic struggles, which prompted waves of immigration to America.
By the time Mr Chan had his first tastes of chop suey, there were relatively few Chinese Americans in the US - 0.08% of the total population - most of whom were descended from Toisan.
"It was like if all the Americans in China were from a small town 100 miles outside of Los Angeles. Very underrepresented," said Mr Chan. As a result, early American-Chinese food tended to be homogenous, had to adapt for local ingredients and catered to an Americanised taste.
But things started to change in the late 1960s. As a new law lifted restrictive quotas on immigration from Asia, the US began to receive an influx of immigrants from mainland China, Hong Kong and Taiwan, bringing in not only modern Cantonese food but also a variety of regional cuisines from across China.
Meanwhile, the American civil rights movement was in full swing, and it inspired Mr Chan, then a college student, to explore his Chinese-American heritage.
In the 1960s, he started to dine at Chinese restaurants listed on the local yellow pages.
"At the beginning, it was just a search for identity," Mr Chan said. "My interest in the history of Chinese in the US led me to eat Chinese food and see what it was like to be Chinese in different parts of the country."
Through this, he learnt of the diversity of the cuisine. He had previously had no idea how varied it was, he said.
Cantonese food, which is known for its bite-sized dim sum dishes, uses light seasoning so that the natural flavours of ingredients can sing. Fujianese cuisine often features seafood served in a broth - the province lies on a coast. Sichuanese food, meanwhile, is famous for dishes heavy on numbing peppercorns and fiery red chillies.
During his long career as a tax lawyer, Mr Chan often sampled Chinese food on his business trips to far-flung states in the US, as well as Canada and Asia.
The best place to find the most varied authentic Chinese foods in America is the San Gabriel Valley in LA, a Chinese immigrant enclave, he said, but for dim sum, San Francisco is the best bet.
He once had "unexpectedly good" chow mein in Clarksdale, Mississippi, which has a historic community of Chinese Americans dating back 200 years. One of his most disappointing meals was in Fargo, North Dakota. "The fried rice was like boiled rice, and somebody poured soy sauce on to it," Mr Chan said. The town is far from any sizeable Chinese communities.
The rise and rise of US-Chinese food
Chinese food has become "democratised" in America over the last decade thanks to an influx of university students from the mainland, thinks Mr Chan. Now, any college town will have a good restaurant that can be enjoyed by all.
Before the recent boom, the event that put Chinese food into the American public consciousness can be traced to a presidential visit in 1972.
The lavish banquet eaten by Richard Nixon with then-Chinese Premier Zhou Enlai in Beijing was televised live across the US, and millions of Americans witnessed their president using chopsticks and sampling dishes of which few had ever heard. Peking roast duck was on the menu, so were fried giblets and lotus seed sweet porridge.
Nixon's visit "prepared for another stage in the development of Chinese food in the US", said Yong Chen, a history professor at University of California, Irvine and author of Chop Suey, USA.
Five months after Nixon's "chopstick diplomacy", the New York Times published an article titled "Chinese Restaurants Flower Following Diplomatic Thaw".
Today, there are more than 45,000 Chinese restaurants across the US, more than the number of McDonald's, Burger King, Kentucky Fried Chicken and Wendy's outlets combined, according to an estimate by the Chinese American Restaurant Association.
And because Chinese restaurants are almost always among the few places open on public holidays like Thanksgiving and Christmas, they have become the refuge of those averse to cooking the big family meal.
Nowadays, Chinese food in America ranges from greasy spoons to sophisticated venues offering a variety of dishes from across China. In major US cities, upscale Chinese fine dining restaurants have also opened doors.
For Mr Chan, this trend presents a bonanza of new Chinese restaurants to "collect". He hasn't set a goal for how many restaurants to visit, he just hopes to try as many as possible.
In retirement, he continues to visit new venues and keeps a food blog.
But one of his followers remains sceptical about his expertise - his wife, who is from China and is bemused that people ask Mr Chan about Chinese food.
In their house, she is the cook.