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 first quarter-final battle it out head to head. First, they have to cook at the one Michelin-starred The Greenhouse in London's Mayfair under chef Antonin Bonnet, and then they have to create two perfect dishes in the MasterChef kitchen. Only one of them can go through.