In this week's episode of "MasterChef," fans will be entertained by Claudia Sandoval's presence and her infectious laughter. The Season 6 winner of the cooking reality show will walk into the kitchen to a resounding applause by enthusiastic Season 7 contestant, Diamond. However, the smiles on each contestant's face could be quickly wiped off because she will set a mystery box challenge that's sure to be difficult.

In Season 7 episode 5, the remaining 17 home cooks will have to deal with not just one but two guest judges while working on their mystery box challenge. Judges Gordon Ramsay and Christina Tosi will also welcome celebrity chef, Aarón Sanchez, to the kitchen and the next minutes of "MasterChef" Season 7 episode 5 will include a cook-off between Claudia and Aarón.

While the contestants don't have to replicate what the guest judges have made, they do have to use the ingredients smartly. In fact, the 17 home cooks will be judged on their clever use of the mystery box along with flavour, presentation and creativity.

Apart from Diamond, the other contestant who will be enthralled by her two favourite guest judges is Andrea. The 21-year-old student from Miami will strive to impress the judges with big, bold flavours, but it remains to be seen if they are indeed surprised by her technique.

The contestants who don't win the mystery box challenge will probably have to take part in an elimination challenge. However, the judges have changed the format of the TV show in Season 7 and could perhaps send one contestant home after judging the mystery box challenge.

"MasterChef" Season 7 episode 5 airs at 8 p.m. EST on Wednesday, June 29, on FOX. You can live-stream the episode via FOX NOW.