Before Thomas Jin pulls the trigger on hiring anyone at his American-style Chinese food restaurant Green Apple Bistro in Studio City, he has a sometimes dealbreaking condition. Everyone, from cook to server, must work on Christmas.

Like most other American Chinese restaurants, Jin sees a massive influx of customers on the December holiday hankering to satisfy cravings for wonton soup, beef with broccoli or a plate of lo mein. It’s by far his busiest day of the year.

That’s the case for just about every Chinese restaurant in the West San Fernando Valley, home to an especially large Jewish population. Eating Chinese food and hitting the local movie theater on Christmas or the holiday’s eve is about as longstanding an American Jewish custom as apple pie.

While the phenomenon has historically a boon for business, restaurant owners say it has in more recent years come to spell real staffing, logistics and even safety challenges at their eateries over the December holiday.

“Christmas Eve is okay, busier than a normal day but not overwhelming,” said Jin from a table at his restaurant on Ventura Boulevard decorated in red and green. “Christmas day, well it’s embarrassing to say, but it’s just unmanageable. At some point we have to stop taking phone orders because we just can’t take it anymore.”

He added that with the amount of food waste from abandoned orders, the extra wages he pays workers and the yearly cook or two who simply doesn’t show up, being the most popular restaurant in town for a day can feel like more trouble than it’s worth.

“Honestly speaking, I don’t make much more money on Christmas. Is it a good thing we’re open? Probably, I can’t say 100% yes. But I can’t close because people will be mad.”

Historians write that the marriage between American Jews and Chinese food on Christmas goes back to the late 19th century, when Jews from Eastern Europe and Chinese people were new immigrants to U.S. cities. “Jews and Chinese were the two largest non-Christian immigrant groups” at the turn of the century,” emphasized producer of documentary In “The Search for General Tso.”

Not only were Chinese restaurants some of the only businesses open on the culturally dominant holiday, but the cuisine’s lack of dairy products meant Jews were less concerned about breaking the kosher dietary restriction of mixing milk with meat.

That said, author of “A Kosher Christmas: ‘Tis The Season To Be Jewish” Rabbi Joshua Plaut points to 1989 as the first recorded documentation of the phenomenon, when the Jewish Journal (a Los Angeles publication) singled out Jews who flocked to non-kosher Chinese restaurants on the holiday.

The new immigrant story morphed into a bonafide tradition, one that has forced Chinese restaurant owners in the LA area such as Jin to make some tough decisions. Some Chinese restaurants in the Valley downsize their food production on the holiday — or even close entirely.

Owners of the casual Garden Wok restaurant in Tarzana decided to trim their Christmas business to to-go orders only. “I stopped being able to handle it,” said co-owner Tin Chiueh.

“Jewish people always tell me that it’s a tradition on Christmas Day and I respect that. But because I let staff take off Christmas we’re short on employees, and it got so crowded that people were stuffing themselves in the restaurant. It was a safety issue.”

Chi’s Chinese Cuisine in Northridge avoids the mess altogether. Though open regular hours for Christmas eve, the institution will close on Christmas Day as it has done for 22 years.

The reason? A holiday spirit of generosity to staff, said co-owner of the family-run business Marco Poon.

Money isn’t everything here,” said Poon. “We want to take care of our family and staff as well. I know that in every Chinese restaurant Christmas Day is the busiest day of the entire year but we choose to spend time with our families and take care of our staff.”