The battle for the last two places in the semi-finals reaches its climax. The first challenge is a knowledge and skills test, where the celebrities have to faceJohn TorodeandGregg Wallaceone by one and demonstrate their ability to identify a tray of ingredients, before being asked to make tempura prawns, vegetables and a dipping sauce in just 15 minutes. The celebrities are then split into teams and are sent out on their first mass-catering challenge, which sees them making lunch at King's College Dental Institute for 120 staff and students. The teams must work with an array of ingredients, including mince, seabass and chicken breasts, and a wide range of fruit and vegetables. It is then back to MasterChef headquarters, where the four celebrities must cook a faultless two-course meal that will not only be judged by John and Gregg but also by past Celebrity MasterChef champions Sophie Thompson and Lisa Faulkner and previous finalist Andi Peters.