Four top chefs compete for the ultra-competitive London and the South East region with canapes, starters and fish dishes. All four are newcomers in the GBM kitchen, representing some of the most exciting new talents in the UK today.

Presenter Andi Oliver welcomes them to the kitchen, where the theme for this year's competition is a celebration of British invention and innovation. One of the four must leave the competition at the end of the episode, as decided by this week's veteran judge.

Today the two highest scoring chefs from the London and the South East region must go head to head and cook their six-course menus again. But will they take on board their veteran's advice as they serve both the panel of judges and one of Britain's foremost geologists?

The chefs need to impress the formidable judges, food writer Matthew Fort, restauranteur Oliver Peyton and broadcaster and food creative Rachel Khoo, as well as a guest judge. In this episode, it's Professor Chris Jackson, a geologist and intrepid adventurer. He judges dishes celebrating British science and innovation, including a lobster dish inspired by a computer algorithm celebrating Ada Lovelace and a dessert paying homage to the discovery of DNA.