The three chefs are halfway through their heat and the pressure is mounting. Each one wants to represent Scotland at a banquet celebrating British invention and innovation. For mains, one chef honours Logie Baird's invention of television with a very upmarket take on a TV dinner, and another celebrates Scotland's successful cloning of Dolly The Sheep. A third chef cooks an ambitious multi-layered pie of beef and chicken with a beef consomme, in homage to the Scottish inventions of Bovril and the hip flask. But whose inventions in the kitchen will veteran judge Tom Brown score highest?Next, presenter Andi Oliver asks the chefs to prepare a pre-dessert or palate cleanser. Veteran judge Tom must blind taste and rank them as they will be used in the event of a tie to decide who goes home. There is a yogurt and berry sorbet coloured to look like a child's toy, and a celebration of Scotland's invention of the first commercial marmalade among the mini dishes to choose from.After a surprise turn in fortunes on the first test of pudding skills, it is on to desserts, often laced with alcohol flavourings. One chef is celebrating a modern-day hero of the Scottish brewery industry with a chocolate and whiskey dessert, while another is celebrating Alexander Fleming's invention of penicillin with a cocktail and ginger cake shaped as individual giant pills. But which chef will prove they have the winning formula to get the top marks? And who will go home?Only two will proceed to Friday's judging and have a chance to represent Scotland at the regional finals.