In the last of the quarter-finals, the best chefs from the week's heats come together in the kitchen to cook against each other and continue in their quest for the title. First, is the daunting invention test. From an array of sweet and savoury ingredients, the chefs are tasked with creating one incredible dish with either herbs, citrus or spices as the core central theme. Will they remember to allow their chosen hero ingredients to shine through their dish? At the end of this challenge, two chefs will be chosen to leave the competition. The remaining four chefs now face one of the toughest rounds of the competition. In an hour and 15 minutes, they must serve up an exceptional two-course menu to three of the country's most notable restaurant critics.