This week's seven best home cooks return to test their culinary wits and try to prove to judges John Torode and Gregg Wallace that they have the potential to be MasterChef champion 2022.

Tonight's challenges are designed to gauge their creativity and culinary repertoire. The first is the Market Challenge, where they must invent a dish on the spot for judges John and Gregg from a market full of ingredients including Bavette steak, plaice and oysters. The pressure is on to impress because at the end of this test one contestant will be sent home.

The remaining six then take on their most demanding assignment so far - cooking a dish to a brief set by one of the country's toughest food critics, William Sitwell. William has asked them to cook a dish inspired by a favourite ready-bought food item - sweet or savoury. The four who produce the best dishes will go through to this week's quarter-final. Who can handle the pressure and show they have what it takes to progress further in the competition?

To kick off semi-finals week, the ten remaining hopefuls are given their first taste of what it's like to work in a restaurant setting. MasterChef turns into a professional kitchen for the day, with judge John Torode running the pass. Tables are laid in the dining room and filled with 20 past MasterChef quarter-finalists, semi-finalists and finalists – all of whom have gone on to have full-time careers in the food industry since taking part in the competition.

The semi-finalists must create a three-course menu that they would be proud to serve in their own restaurant or put in a cookbook. Split into three groups, three contestants must each cook their starter, four must each cook their main and the remaining three their dessert. With John running a tight ship, it's up to the teams to bring all their orders to the pass upon call of service. It's feedback from the dining room, however, that lays bare how the contestants cope with a service environment. They hope to receive rave reviews, but instead could fall behind the pack.

At the end of this mammoth task, two contestants will be saying goodbye to their dream of becoming MasterChef champion, while the remaining eight continue to the next round.