Prince William and Kate Middleton star in BBC One's festive show with Mary Berry

Prince William and Kate Middleton are serving up a holiday treat for people who will have a working Christmas. The royal couple requested British TV cookery show host Mary Berry to help them spread festive cheer to people connected to their charities who won't be able to relax with their families over the holiday season.

The Duke and Duchess of Cambridge make an appearance in the show titled, "A Berry Royal Christmas" that will air on BBC One on Monday, December 16. In the BBC special Mary Berry rustles up some of her favourite recipes while Prince William and Kate Middleton can be seen in the kitchen helping set up the event, Hello reports.

The festive cookery show will highlight some of the causes close to William and Kate. Last month the 37-year-old duchess hosted a Christmas party in Rosewood Hotel in London. Berry came up with recipes for the party.

William and Kate wore their aprons and set to help the former "Great British Bake Off" winner Nadiya Hussain and Berry lay down a delicious spread. The couple's lucky guests got to taste among many things Christmas Meringue Roulade. The guests included nurses, emergency services workers, staff from a mother and baby unit and armed forces personnel.

The entire event was filmed by Shine TV for the BBC as part of an hour-long TV special.

Earlier the royal couple took Berry along to visit some of their charities and organisations closest to their hearts, to give her a feel of why they are so passionate about supporting them.

In the show, William pays tribute to his grandparents and parents for their for their charity work over the years. "Growing up both of my parents were hugely charitable. My father set up the Prince's Trust. He's involved in so many different organisations. My mother has done her work with homelessness and as you said AIDs and other charities and I think I've grown up in a household which has been very much a case of 'well, we're very lucky - you must give back," he said speaking to Berry.

The 37-year-old prince added that his grandmother became queen at a very young age and made a difference "in her own very unique, distinct way."

William said: "I find that you hear and you understand and you learn so much more by giving a bit of your time, a bit of your day, to just be around."

A source said that the TV appearance was the duchess's most substantial to date. The insider added that it was "heart-warming". "The conversations they have really pull on the heartstrings. You get a really good sense of who she is – maybe more so than before," the insider added.

This is not the first time the Duke and Duchess are bringing some festive cheer for the less fortunate. In February, William chopped carrots and served spaghetti Bolognese to a group of people. The couple prepared soup and bread to youngsters at a centre in Barnsley, south Yorkshire.