Prince William and Princess Catherine have a certain set of rules their children must follow as part of royal protocol.

But Darren McGrady, who worked as a chef in Buckingham Palace for 15 years, lauded the Prince and Princess of Wales for continuing on with royal tradition.

McGrady said that the couple’s three children — George, Charlotte, and Louis — weren’t allowed to sit at the dinner table with the adults until “they have learned the art of polite conversation”.

What’s more, McGrady said, the rule was always in effect — even during special occasions like Christmas.

The rule continues traditions followed when William and his brother, Prince Harry, were children.

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McGrady said that the royal families’ nannies, then and now, weren’t just responsible for disciplining the children — they were also responsible for “educating their palates”.

He explained: “The royal nursery wasn’t just for educating the minds of the young royals but educating their palates, too.”

“Nanny always had control of the menu and made sure they ate balanced meals that included not only lots of healthy vegetables but introduced them to new grown-up dishes too.”

As with most children, getting the royal children to eat their vegetables proves to be a bit of a task — and that was even true when William and Harry were children.

However, McGrady said, he’d come up with a clever way to inspire them into eating veggies.

He would hide the offending vegetables into some of their favorite foods, like cakes and sweets.

Of course, McGrady confessed, being a royal doesn’t stop the occasional treat, too — because just as Princess Diana would take her sons to McDonald’s for the occasional burger and fries, so too do William and Kate from time to time.