The common ingredients and ordinary foods strictly banned from royal palace kitchens

One surprising ingredient the royals steer clear from is margarine.

Former royal chef Darren McGrady told Smooth Spins Casino: "Never cook anything in margarine. In fact, ban it from the kitchen. Even flies don't like margarine – it's nasty."

While margarine is not inherently bad, it is an ultra-processed food, meaning it often contains artificial ingredients or colours. Instead, Darren suggested butter as the better and far healthier choice for cooking. While butter contains more fat, it is less processed, making it the preferred option for royals who favour a healthier diet.

During Queen Elizabeth II's reign, the royals would never eat fresh truffles, as they were considered an indulgence. "The Queen loved scrambled eggs with smoked salmon and a grating of truffles. But she was too frugal to ever order fresh truffles," said former palace chef Darren McGrady to The Telegraph.

This is hardly surprising considering Elizabeth grew up in wartime, when everything from butter and sugar to tea and soap was carefully rationed. However, she would splash out on the luxurious food at Christmastime, when the royal family were sent truffles as presents.

Another food that is surprisingly banned from the palace is the humble square-shaped sandwich, all thanks to an age-old superstition.

“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," said former royal chef Graham Newbould in his documentary Secrets of the Royal Kitchen.

Graham added that he "never once prepared square sandwiches" for Queen Elizabeth, and instead would serve up "jam penny" sandwiches – crustless round white bread sandwiches with a layer of jam in the middle.

Royals tend to avoid eating shellfish both at home and abroad, due to the higher risk of food poisoning.

“When dining, the Royal Family has to be careful with shellfish due to shellfish poisoning, due to their work schedules. Therefore, you will not normally find this on the royal menu," Grant Harrold, former royal butler, told the Daily Express. 

If they were to come down with food poisoning, this could disrupt their royal schedules, which are typically packed to the brim with military visits, ribbon-cutting and public engagements.  

The royal family generally stay away from rare or raw meat, like steak tartare or sashimi, for the same reasons that they skip the shellfish – to avoid food poisoning.

Garlic is also banned from the palace kitchens, due to its strong smell and ability to make one's breath rather pungent. "The Queen didn’t like garlic or strong onions, viewing them as antisocial," said Darren McGrady to Heart Bingo. “So we didn’t use garlic in her meals.”

Queen Camilla confirmed this during an appearance on MasterChef Australia, sharing: "Garlic is a no-no...You always have to lay off the garlic."

Foie gras, which is made from the fattened liver of a duck or goose, is completely banned from being served in royal residences, due to the cruel way the animals are treated to produce the dish.

"As Prince of Wales, King Charles removed foie gras – a despicable product for which ducks and geese are force-fed until their livers swell up to 10 times their natural size before the animals are slaughtered – from his royal residences," said a spokesperson from animal rights organisation PETA in 2022.

"Now, PETA has received confirmation that His Majesty's compassionate policy extends to Buckingham Palace and all other royal residences."

"I can confirm that foie gras is not purchased by the Royal Household nor served in Royal Residences, and there are no plans for this policy to change," said the letter PETA received from royal officials."

Out-of-season foods are out of the question for the royals, as Darren McGrady told Heart Bingo. “The Royal Family eat by seasons,” he explained.

“If I put strawberries on the menu in January, there would be a huge thick black marker through the menu book deleting those strawberries. 'How dare you even suggest strawberries in January' – King Charles would have the same feedback on this too."

She would, however, give the fruit a tick of approval during her summer stays in Balmoral, as it was in season. He added that Elizabeth would approve the fact that Easter at Windsor Castle entailed "lots of spring dishes, a lot of lamb on the menu and a lot of fish".

While starchy foods like pasta, rice and potatoes are not altogether banned in the palace, Elizabeth preferred to avoid them when eating by herself. This is because starchy foods can cause general sluggishness due to a spike in blood sugar followed by a rapid drop in energy, which would not do for the busy monarch.