William and Kate were visiting the charity’s centre in Barnsley, South Yorkshire, when they were asked to help prepare lunch before serving food to two of the young people who have been helped in the town.
The couple looked relaxed as they chatted with staff and young people, with the duke joking it was far from a normal lunch as he gestured to the photographers and reporters ranged in front of him.
Kate, wearing a blue Eponine dress, arrived with William after the couple had opened a new £50m McLaren supercar factory in the Advanced Manufacturing Park between Sheffield and Rotherham.
William said he looked forward to seeing more of the supercars on the roads after he and Kate Middleton were shown around McLaren’s Composites Technology Centre (MCTC).
The royal couple was joined by the Crown Prince of Bahrain, Prince Salman bin Hamad bin Isa Al Khalifa, who is one of McLaren’s main shareholders.
The site aims to be a world leader in innovating lightweight carbon fibre tubs that are integral to the agility and performance of McLaren’s supercars and sportscars.
McLaren chief executive Mike Flewitt said the firm’s first factory opened in Woking seven years ago and now more than 90% of its products are exported worldwide.
He said: “We already have over 50 talented, dedicated pioneers working here in the region, many drawn from the local area, many met the Royal Highnesses this morning.”
Mr Flewitt said by 2020 the site would employ more than 200 people, bringing McLaren’s total workforce to 3,500.
The Yorkshire site “was more than simply a factory”, Mr Flewitt said, adding: “Although manufacturing is an important part, it’s an innovation centre, a place where new technology will be developed.”