In the slow growth restaurant environment, chains have a few options for boosting business: build more locations, generate higher sales at existing ones or develop an offshoot brand.
Several restaurant companies are opting for the third route and testing concepts that offer an additional stream of revenue without cannibalizing the success of their existing locations.
"They ultimately see future growth opportunity either declining or limited so they look for new opportunity in the industry for growth," said Darren Tristano, executive vice president at Technomic, in a phone interview.
"Everyone wants to be a growth chain because valuation is higher," Tristano added.
The concepts can also serve as a test kitchen for restaurants to try out new ideas that could trickle down into their flagship brands.
Several of these chains want to capitalize on the speedy growth of the fast-casual segment, which has eclipsed that of the overall restaurant space.
"Right now, everyone is looking at fast casual," Tristano said. "It's the right price, right quality and right appeal for consumers."
Click ahead to see what restaurants are cooking up to boost growth.
—By CNBC's Katie Little
—Last updated March 4, 2015