Members of the Royal family are bound by a myriad of traditions and protocols, with one particularly quirky rule concerning their lunchtime fare.

A past Royal chef has spilled the beans on an unusual superstition that’s been handed down through generations, affecting even Prince William and Princess Kate’s choice of sandwiches. In the TV documentary ‘Secrets of the Royal Kitchen’, Graham Newbould revealed why you won’t find square-shaped sandwiches on the Royal menu.

He explained that there’s a belief within the palace walls that pointed food could signify malevolent intentions towards the monarchy, thus influencing the Royal chefs’ preparations.

He disclosed: “The royals never have square sandwiches because tradition has it that anyone presenting them with pointed-edged food is trying to overthrow the throne of England.”

Prince William and Princess Kate (Image: Getty Images)

Having served at Buckingham Palace for two years and Kensington Palace for six, Newbould never prepared square sandwiches for Queen Elizabeth II, as reported by the Express. The late Queen had a preference for “jam penny” sandwiches, which were part of her afternoon tea ritual, reports the Mirror.

Square sandwiches aren’t the only thing you won’t find on the Royal menu. Royal chef John Higgins once revealed: “At Buckingham Palace, you don’t cook with garlic. I suppose, in case you get the Royal burp.”

This rule, mainly enforced during Royal events and state banquets, was also confirmed by Queen Camilla in 2018.

During an appearance on MasterChef Australia, when asked about forbidden Royal foods, Camilla admitted: “I hate to say this, but garlic. Garlic is a no-no.”

Judge Gary Mehigan then queried: “So garlic is a no-no? Because you’re talking, chatting?” To which the Queen responded: “Yes, exactly. So you always have to lay off the garlic.”

Another food item that’s off-limits for the royals, particularly during Royal events or tours, is shellfish – all to avoid the risk of food poisoning. Grant Harrold, former butler to King Charles, revealed: “When dining, the Royal Family has to be careful with shellfish due to shellfish poisoning, due to their work schedules. It is a very sensible move to abandon having seafood when out and about on public duties. We don’t want a member of the Royal Family having a serious reaction to food poisoning. Especially if [they] are on an overseas tour. Therefore you will not normally find this on the royal menu.”

Meanwhile, King Charles has taken a stand against foie gras, removing it from all menus at his Royal residences due to the unethical production methods. Foie gras, a controversial delicacy made from the enlarged liver of a duck or goose suffering from hepatic steatosis, is recognised as one of the most expensive dishes in the world.