In the second quarter-final, the four best chefs from the week's heats return to the kitchen. Tonight, they must prove themselves to Anna and Marcus in two challenges that would unnerve even the most experienced chefs.First, Anna and Marcus set the contenders an Invention Test with a twist. They must create a dish that showcases as many different textures as possible using a larder that includes seafood, fish, meat, fruit, vegetables, spices, nuts, pastas and pulses. Starting from scratch, who will best use the 70 minutes to deliver a plate full of contrasting textures that also tastes delicious?Next, the chefs must raise their game yet again when they cook for food writers Leyla Kazim, William Sitwell and Grace Dent. With a two-course menu of their own design, this is their chance to catch the eye of three people whose word can make or break careers.Only the most talented chefs will make it through to the semi-finals.