We tried Shake Shack's new chicken sandwich - here's the verdict

Shake Shack just came out with its first ever chicken sandwich.

The so-called ChickenShack, which has been two years in the making, features crispy fried chicken, lettuce, pickles and buttermilk herb mayo between two toasted buns.

The sandwich will only be available for a limited time this summer at Shake Shack's Brooklyn locations, but it could be rolled out nationwide if it's successful.

So we decided to test it out.

When we arrived at Shake Shack, an employee greeted us at the door with a menu prominently featuring an ad for the new sandwich.

The ad told us that the sandwich was 600 calories and cost $6.29.

We ordered two of the sandwiches and a small serving of fries. Less than 10 minutes later, we had our food.

The first bite was packed with flavor.

The chicken was hot and juicy with a hint of buttermilk flavor and the fried breading was crisp and crunchy.

There was also a spicy kick from black pepper, cayenne, and smoked paprika in the breaded crust.

Shake Shack culinary director Mark Rosati told Business Insider that the sandwich was inspired by the South.

The meat is marinated in buttermilk, which gives it flavor and tenderizes the chicken, he said. There are also pureed vegetables in the buttermilk marinade to give it an extra kick.

The pickles add a vinegar flavor to cut through the richness of all the other ingredients and the lettuce is meant to add some crunchiness, he said.

The herb mayo is flavored with thyme, parsley, chives, and buttermilk to complement the marinade.

Our verdict? Delicious. We finished every last bite.

Shake Shack is carefully measuring customer reactions to the new menu item.

The company had several employees canvassing the Brooklyn restaurant, asking customers to take surveys on the ChickenShack.

About 80% of customers at that location ordered the ChickenShack for lunch on Tuesday, the canvassers told Business Insider. (It was still early, before noon.)

Rosati said he came up with the idea of adding a chicken sandwich two years ago.

"I was hungry for lunch and I didn't want a burger," Rosati said.

While there are no plans right now for a national rollout, Rosati said he could see the ChickenShack "living in harmony alongside the burger" at Shake Shacks nationwide.