A trendy NYC restaurant didn't find out the Obamas were coming for dinner until 5 minutes before they arrived

When the Obamas showed up for dinner at Cosme last Monday night it was a surprise to everyone, including the restaurant's maître d', its waiters, and even its chef.

That's because when the Barack and Michelle Obama go out to dinner, they make a reservation under a pseudonym and only let the restaurant know they're coming a few minutes in advance.

I know this because I dined at Cosme, a trendy Mexican restaurant in New York City's Flatiron District, last Monday night. And on my way in I got the chance to talk to the president's security detail as they searched my purse and frisked me.

The Secret Service officer I spoke told me that this was protocol, and most restaurants don't know they're coming. Cosme declined to comment for this story.

During the meal at Cosme, the Michelle Obama and the president were seated behind closed doors in a private dining room. We couldn't see them eating, but we did get a glimpse of them leaving at the end of the meal.

The Obamas came in and entered through the restaurant's front entrance. Their armored limosine, nicknamed "The Beast" was parked outside the entire time, and the block was closed to cars. The restaurant was swarming in Secret Service agents the entire time.

The Obamas reportedly ordered off the restaurant's regular menu, and got Cosme's famous duck carnitas.