It's the semi-final, and it's social media week. Only four cooks remain to fight for a place in the final, and the mentors are turning up the heat with their toughest set of challenges yet.This week's Level Up challenge is to transform everyday biscuits into decadent desserts that not only taste delicious but also look good enough to go viral.For the Service Challenge, the hub is transformed into a street food festival, and each of the cooks is tasked with running their own street food stall, with a menu that showcases the sort of food business they would like to have in the outside world. The cooks are not only judged on taste, but also on how likely their food is to make a noise on socials.In a dramatic Knives Out, the bottom two cooks must make one of Kayla's favourite dishes: fish tacos. But at the end of the day, one more cook must go home and narrowly miss out on a place in the final.