The little cooks from MasterChef Junior season 5 were stunned to learn that they would face a tough challenge given to them by none other than Michelle Obama. And, the former first lady surprised the contestants with the toughest mystery box challenge, which is to make simple and healthy food.

In a promo for the upcoming episode, the top 14 mini chefs will be highly surprised to see the challenge. "It's a mystery box inspired by the White House kitchen garden," the former First Lady says to the young amateur cooks who has their cooking platform filled with freshly picked tomatoes, apples, eggplant, berries, peppers, fish, prawn, minced chicken and more.

"One of my greatest passions is making sure that kids like you have the nutritious food you need to grow up healthy. So, for your mystery box challenge, I'm asking all of you to come up with an original recipe that's healthy and follows the MyPlate symbol, filling half your plate with fruits and veggies and the rest with whole grains, lean protein and dairy."

Jasmine from Milton couldn't hide the excitement as she sees her idol on the monitor. "I'm, like, about to die. R.I.P. me. Oh my god. I mean, Michelle Obama is a Wonder Woman and I look up to her so much—she is my idol," she says.

Though the challenge sounds like a great idea for few, Donovan don't think he can do justice to the veggies. "Michelle Obama wants me to cook vegetables. Not happening. I don't like vegetables. They're evil," he says.

Apart from the mystery box challenge, Gordon Ramsay and Christina Tosi and guest judge Julie Bowen will ask the contestants to cook a special dish inspired by their mother. It will be interesting to see who successfully faces challenges and who will go home after it. MasterChef Junior season 5 episode6 will air on Fox on 16 March.