Double-Michelin-starred chef Michel Roux Jnr and MasterChef dining expert Gregg Wallace ask two of their skilful semi -finalists to step up to service at London's two star L'Atelier de Joel Robuchon, famous for its French cuisine with Spanish and Japanese influences. Working under head chef Olivier Limousin, they must now compete in the heat of service and reach the exacting standards of two Michelin star cuisine. They will each be responsible for a highly complex dish that must be executed with precision, finesse, and on time. No mistakes will be tolerated. Then, the bar is raised higher as Olivier asks them to recreate one of his favourite signature dishes: caramelised lamb sweetbreads with maple syrup walnuts, fresh almonds, pine nuts, served on blanched cabbage leaves, sauteed root vegetables and a lamb jus. With so many elements to balance, it's a battle for the chefs to reach the dizzy heights required. Then, the two semi-finalists return to the studio for one last challenge before one of them will be sent home. In this daunting final test, they must produce a main and dessert inspired by their Michelin experience in just two hours - they simply have to blow the judges' minds. Any mistake could cost them the competition so with the pressure firmly on, it is a tense and thrilling battle. Once Michel and Gregg have judged their two courses, they must decide which chef will leave the competition. At the end, only the very best chef will win a place in the finals and have the chance to become this year's champion.

• Gregg Wallace
• John Torode
• India Fisher