At first glance, the Shake Shack in New York City's West Village looks like any other fast, casual restaurant.

When you peek through the window, you'll see customers eating burgers, chicken sandwiches, and crinkle-cut french fries.

But in the back of the building, you'll find a staircase that leads down to a secret kitchen.

Down here, underneath the city, chefs are busy inventing Shake Shack's next big menu item.

The ideas for a new item can come from anywhere, anyone.

The Innovation Kitchen is the place.

We'll dissect those ideas and look for ways in which we can explore them.

That's John Corrangis, the vice president of culinary innovation at Shake Shack.

He's in charge of the menu at the restaurant chain's nearly 600 locations worldwide.

He oversees a team of around 10 people who work in the chain's test kitchen, the place

where many of their famous burgers are born.

I kind of gravitate to the smoke shack, which is a delicious simple bacon cheeseburger.

Oh, yeah.

It has some cherry peppers on it, which gives it just the right amount of heat and acidity to balance

out some of the richness.

It might not seem so tough to cook up something like a bacon cheeseburger, but creating

a delicious new menu item that can be served consistently and cost effectively thousands

of times a day around the world, that's a different story.

We're tweaking, we're honing, where we're finding.

Our process requires lots of specialists from several teams to make sure it all comes together.

It takes about a year and a half from idea to actual launch on a menu.

For the Freakonomics Radio Network, this is the economics of everyday things.

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