Overview: It is the semi-finals for the professional chefs remaining in the competition, and each pair of winners from the quarter-finals go head to head for a place in the last four. The two winners from the third quarter-final battle it out head to head. First they have to cook at the one Michelin-starred Maze in London's Mayfair, under chef Jason Atherton. Then they have to create two perfect dishes in the MasterChef Kitchen - only one can go through.