It's the last week of the heats and five ambitious chefs from kitchens across the country begin their bid for the title when they face their first challenge - the Signature Dish Test. With just one hour to cook a stunning plate of food that truly showcases their talent, the professional chefs must pull out all the stops to impress the judges. After this test, the judges must send one chef home. In the feared Skills Test, Monica asks the remaining chefs to prepare and deliver a cuttlefish dish in just 15 minutes. It's a tough challenge, especially for those chefs unfamiliar with prepping such an ingredient, but they must draw on all their culinary knowledge and hold their nerve if they are to impress. Any mistakes now could seriously damage their chances of continuing in the competition. It is then up to the chefs to raise their culinary game as they face Marcus Wareing's version of the Invention Test. First Marcus demonstrates one of his favourite recipes to viewers at home. This time it's his classic sweetbread dish - Pan-fried sweetbreads with wet polenta and confit lemon. The chefs are then given the main ingredient of sweetbreads and a larder containing the rest of the components in Marcus's dish, as well as an array of other high quality ingredients. In their final chance to impress, the professional chefs have just ten minutes to compose and one hour to cook an inspired plate of food that will prove they are worthy of a quarter-final place.