A contestant on Masterchef slices up apples as they prepare a dish for the Apple Mystery Box Challenge.

Sav picks out some apples for a dish she intends to impress the judges with during the mystery box challenge.

The chefs experience their first mystery box challenge and it's a challenge with apples as the ingredient.

It's time for the Mystery Box on MasterChef. "Apple Mystery Box" is the sixth episode of the show's 13th season.

Aaron Sanchez in the special 2-hour episode of MASTERCHEF airing Wednesday, Aug 31

Contestant Kennedy with judges Joe Bastianich and Aarón Sánchez in the “State Fair” episode of MASTERCHEF airing Wednesday, June 21

Aarón Sánchez in the “Tag Team” episode airing Wednesday, Aug 17

Aarón Sánchez in the “GrubHub Challenge” episode airing Wednesday, Aug 17

Judge Aarón Sánchez in the “State Fair” episode of MASTERCHEF airing Wednesday, June 21

This is a photo of Chef Aarón Sánchez for MasterChef Junior.

The contestants from all regions tackle their official first challenge of the season on Masterchef.

West coaster, Amanda, is slicing and dicing away as she prepares a dish for the first challenge of the season.