Watch 24 in 24: Last Chef Standing

Co-hosts Michael Symon and Esther Choi begin the second shift with two chefs in a head-to-head elimination battle that tests simplicity. Their assignment is to turn a basic sandwich plus three ingredients of their choosing into a fancy lunch. After judge Graham Elliot decides which chef will clock out, the 12 remaining chefs must use the simplest of tools -- their palate -- to pass a tricky test that impacts their ability to survive a second elimination challenge. It's only hour four, so the chefs are still running on adrenaline and energy ... for now!

In the supersized season premiere, hosts Michael Symon and Esther Choi welcome 24 of the country's most talented and fearless chefs to compete in the most intense competition of all time – 24 challenges in 24 nonstop hours. In the first shift, the chefs must endure three challenges testing speed. Those that impress expert judge Antonia Lofaso survive, and whoever does not is forced to clock out. When Michael and Esther introduce the all-important golden knife, the chefs learn this epic day of cooking will be full of twists and turns, but only those that can adjust on the fly have a chance to be the last chef standing. Over the next 24 hours, the competition tackles different shifts that test aspects of being a chef: after the premiere's speed challenge, themes include simplicity, resourcefulness, artistry, adaptability, teamwork, risk taking and elevation.