The heat continues with the four remaining celebrities fighting for a place in the semi-finals. The first challenge they face is a knowledge and skills test, where they have to demonstrate their ability to identify a tray of ingredients, three root vegetables and three birds before being asked to cook a duck breast with swiss chard and a caper butter sauce. The celebrities are then split into teams and are sent out on a mass-catering challenge, which sees them making lunch for staff and players at The Oval cricket ground. With an array of ingredients, the two teams must devise, prepare and serve the lunch. It is then back to the MasterChef headquarters as the battle for semi-final places reaches its climax. The celebrities must cook a faultless two-course meal that will not only be judged by John and Gregg but also by 2016's Celebrity MasterChef champion Alexis Conran and finalists Louise Minchin and Sam Nixon. Only the best two contestants can earn a semi-final place.