When the last two Swiss Chalet rotisserie chicken restaurants in the United States – one in Amherst, one in Depew – went dark on Feb. 28, 2010, Western New Yorkers who grew up with the chicken, fries and sauce at the center of family nights, first dates and happy birthdays did the only thing they could:

They got their passports ready, pointed their vehicles toward Canada and planned pilgrimages to the land where Swiss Chalet was born.

“Lots of Americans come once a week,” said Robyn Hildebrand, manager of one of the Niagara Falls locations, a shiny standalone store on Montrose Road with a drive-thru. “Some come multiple times a week. They usually have a list with them, of friends, people they know, orders to bring back for people in the neighborhood.”

The border guards were among the first to notice the trend, followed by the staff at the Swiss Chalet on Lundy’s Lane in Niagara Falls, Ont.

“I have a couple that comes once a week, from Rochester, an hour and a half’s drive,” said manager Wayne Deline.

For the Western New Yorkers who worship at the Swiss Chalet altar, Facebook is the minaret, the platform most often used to call the faithful.

It goes like this: An Internet-capable fan of the Canadian chicken chain posts a photograph lovingly detailing the holy trinity: a quarter chicken, fresh-cut french fries and brick-red dipping sauce.

If they grew up around here, a certain part of the audience will feel a stirring, a hunger whose source they cannot always name, but with its roots in their childhood; a hunger amplified by the fact that since 2010, satisfaction has required international travel.

Today, Americans account for 5 to 10 percent of the volume at the two Niagara Falls, Ont., stores. If the Department of Homeland Security scanners at the border checkpoint sniffed for Swiss Chalet’s signature dipping sauce, a lot more trunks would get popped. “A lot of people, they’ll come over and order 20 large sauces,” said kitchen manager Matt Stewart. “Lord knows how they get it back over the border, but they do.”

Lord knows.

“A lady came over with those plastic gallon jugs – milk jugs? – and filled up 30 or 40 of them,” said Deline. “She was going to auction them off at the church bazaar.”

Bizarre is what the passion of the Swiss Chalet pilgrims is to nonbelievers, which is to say most people. Rotisserie chickens have proliferated in restaurants and grocery stores, satisfying most customers’ pressing poultry needs. Cara Operations, the Canadian company that owns Swiss Chalets among its 700 restaurants, didn’t turn out the lights for nothing.

When you ask the pilgrims to explain the pull, though, you end up talking about more than money. You end up talking about the pure childish joy of dunking fries in sauce.

Raised on Buffalo’s West Side, in a family of six, Connie Berti was introduced to Swiss Chalet on Main Street, in the former Laube’s Old Spain space. “Even in elementary school ... Swiss Chalet was affordable, it was reasonable, and you got a nice meal.”

There was nothing comparable, she said. “You didn’t eat much chicken out those days. Then they make fresh-cut french fries. Never been frozen. That’s the other factor: a delicious french fry.”

The sauce sealed the deal. “It wasn’t something your aunt made, or your mother, or your grandmother,” said Berti, who is Sicilian and knows her way around a sauce. “It was just different and explosive on your taste buds when you dipped chicken in it.”

The most unusual thing “was that at the end of your meal, they would bring you a little bowl, with warm water and lemon in it, to wash up,” she said. “Guess what? They still do that.”

Berti and her husband, Bob, brought their children, and another generation of Swiss Chalet fans were imprinted on the sauce. When the last store closed in 2010, after “lots of tears and unhappiness,” Berti said tongue-in-cheek, “I searched the Web to find if there was another one.”

Which brought her to the border – four times in 2012, and once this year. Sometimes, in a pinch, she oven-roasts a chicken “with a little smoke flavor on it” or buys a ready-made rotisserie bird, and pulls a packet of Swiss Chalet dipping sauce powder from her emergency stash, to simmer her own. “We have that in a pinch,” she said.

The packets are available at Canadian supermarkets such as No Frills for about $1 each, or at Redlinski’s in Cheektowaga. “I give them away to other Swiss Chalet addicts,” said Berti. “When I was ordering them online, I was very careful about who I gave them out to. Now I dole ’em out like candy.”

To Canadians, Swiss Chalet’s main appeal is the food. Freshness is the mantra. If a chicken hasn’t been sold in 45 minutes after coming off the roaster, it’s turned into chicken meat for soup and sandwiches. The fries, fresh cut and cooked twice for a superior crisp? Five minutes unsold and they go into the trash, said Stewart, the kitchen manager. “The head office comes in to make sure,” he said. “Fresh is guaranteed.”

Swiss Chalet had about two generations for the sauce to seep into the locals’ DNA. That was enough.

“As somebody who considers [himself] a pop historian of Western New York and Buffalo, there was something very Buffalo about that place,” said Steve Cichon, news director for WBEN 930. His family were regulars as he grew up in Orchard Park, and it was part of the “dating rotation” with Monica, now his wife of 12 years.

“It was one of those places you think of when the plane lands, and people ask, ‘Where are you going to go first?’ ” Cichon said. “We all became ex-pats, in a way, when Swiss Chalet closed. It was part of the taste of Buffalo, for so many people, that was gone.”

So Cichon’s heart goes out to the hungry who holler every time he posts a photo to Facebook.

“People go crazy,” he said. Needlessly, in many cases, he pointed out. “It’s not that far away, if you have a passport or enhanced license,” Cichon said. “It’s 25 minutes from the [Peace] bridge. There is a border between us, but it’s not that far away.”