It's fast food week, and the temperature is turning up in the kitchen as the final five battle for a place in the semi-final.The cooks' Level Up challenge is to transform ordinary instant noodles into extraordinary and innovative original dishes.In the evening, the cooks take part in a yoga class to build some relaxation into their busy schedule, but the session provides more than just physical release for one of the cooks.The menu for this week's Service Challenge is Mexican fast food. Guest judge Sarah Newman from Mexican fast food chain Tortilla announces that the prize this week is for the winning cook to get their salsa recipe on the menu nationwide in over 50 restaurants.At the end of the day, the bottom two cooks must battle it out in the most challenging Knives Out elimination to date – Chinese pot-sticker dumplings with an aromatic dipping sauce. After a dramatic contest against the clock, one more cook is sent home, narrowly missing out on a place in the semi-final.