As the third week of heats begins, five more amateur cooks try to prove to judges John Torode and Gregg Wallace that they have the potential to be MasterChef Champion 2015. Firstly, the contestants are given just one hour and fifteen minutes to dazzle the judges when they are asked to cook their calling card, a practised dish that represents just who they are as a cook and showcases their talent. The two lucky cooks who do best will be safe - for now - and sail straight through to the third test. The remaining three contestants must cook again in a twist on the infamous invention test - the reinvention test. The hopefuls are given the main ingredient from their calling card dish as well as access to the larder. Using that same ingredient they must reinvent the dish to create a brand new plate of food that will sway the judges and earn them a place in the next round. It's the end of the road for one person after this cook-off. To earn their place in the quarter-final, the four remaining cooks have to cook a menu that will impress not just John and Gregg but also some of the competition's most inspiring winners and finalists. In this episode 2008 champion James Nathan, 2011 champion Tim Anderson and 2007 champion Stephen Wallis are back to give their verdicts. After the four contestants have cooked, John and Gregg decide which two will take the next step in the competition and go through to Friday's quarter-final. In a competition where only the food matters, these amateurs will need to be good to survive - taking their first steps towards being crowned MasterChef Champion 2015.