With Portland, Maine-based O'Naturals set to expand its seven-unit base, a bigger slice of America will get its first taste of the chain's Wild West sandwich. Featuring wild-bison meatloaf, the $7.10 sandwich is baked and served warm on signature flatbread with roasted red peppers, cheddar cheese and stone-ground mustard. (Lettuce, tomato and red onion are optional.)

Among the top three sellers on the sandwich menu since its launch in 2003, the sandwich was O'Naturals' solution for how to keep bison on the menu after it dropped both beef and bison burgers.

“When we started the concept, we thought the world needed a better burger and that guests would crave that,” says Vice President and Chief Operating Officer Jay Friedlander.

O'Naturals' guests, it turned out, craved otherwise. They preferred flatbread sandwiches, salads and noodle bowls, even though the two burgers O'Naturals menued were top quality—one made with Angus beef, the other, wild bison.

“Wild bison actually outsold the beef by a long shot,” says Friedlander. But even so, burgers just weren't big sellers. Taking its cue from guest behavior, O'Naturals dropped burgers by its first anniversary, year-end 2002.

But burgers or no, O'Naturals wanted to keep wild bison on the menu. Sourced from Western herds that are part of a Great Plains restoration project, the meat “not only tastes good, it's part of a good cause,” says Friedlander.

The team re-introduced bison in 2003, baked into meatloaf, sliced and sold on flatbread as a sandwich. This time, guests loved it, Friedlander says. The Wild West has been one of the top three sellers in the sandwich category—No. 2 during cold weather months—ever since.