In this quarter-final, the week's best chefs return to continue their quest for the title. Their first challenge is an invention test set by Monica and Marcus. From a table filled with citrus, herbs and spices, they must create something truly special to impress the judges. They have 10 minutes to decide, then 70 minutes to cook their hearts out and create a dish from scratch, which allows the flavours of their chosen ingredients to shine through. At the end of this round one chef leaves the competition - so it's now or never.

The remaining chefs now face the critics - a test that has seen even the best fall apart under pressure. They must cook a two-course menu of their own design to be scrutinised by the judges and three of the UK's most renowned critics - Tracey MacLeod, Jay Rayner and William Sitwell. They have one hour and 15 minutes to dazzle the critics with an inventive main course and knock-out dessert. Get it right and the critics may note down a future star, but get it wrong and it is game over.

The three chefs who wow the critics and judges will make it through to knockout week, when the competition really hots up as they inch closer to the possibility of lifting the Professional MasterChef 2017 trophy. Show less