Prince William was taught how to cook lasagne to impress his wife.

Prince William and Duchess Catherine

Prince William and Duchess Catherine

The 35-year-old royal was told by chef Giada De Laurentiis what the "key to a great lasagna" was so he could impress Duchess Catherine.

She said: "I remember meeting him and he told me the exact same story and asked me what was the key to a great lasagna ... [I told him] you've got to make sure that you have enough sauce to get a nice crust on top and you've got to let it sit before you cut into it. It has got to set, otherwise it'll just be a pool of mess."

The pair met at the Foundation Polo Challenge in Santa Barbara, California, when Giada was asked to cook for the royal couple.

She told POPSUGAR: "I was floored when they gave it to me. There's been a lot of things that I've done, and in my work life, it's probably one of my highlights ... I was hoping that if they picked me, somehow I would give him a tip when we met about what makes a great lasagna."

Prince William and Duchess Catherine's relationship is going from strength to strength after it was revealed the couple are expecting their third child.

A statement from Kensington Palace about the royal couple - who have Prince George, four, and Princess Charlotte, two - shared: "Their Royal Highnesses the Duke and Duchess of Cambridge are very pleased to announce that the Duchess of Cambridge is expecting their third child. The Queen and both their families are delighted with the news.

"As with her previous two pregnancies, the Duchess is suffering from Hyperemisis Gravidarum. Her Royal Highness will no longer carry out her planned engagement at the Hornsey Road Children's Centre in London today. The Duchess is being cared for at Kensington Palace."