The Queen and Prince Philip may not have the exact same taste in food, but they do agree that one item should never be on the royal menu – oysters!
READ: The Queen's daily diet: The monarch's breakfast, lunch and dinner revealed
Despite being a delicacy in many countries, the seafood is avoided by the couple, according to former royal servant Charles Oliver.
"Inevitably there are one or two things the Queen and her husband do not like, and the hosts are duly warned in advance," reads an extract from Dinner at Buckingham Palace, based on the diaries and personal recollections of Charles.
"The palace instruction states only: 'Neither the Queen nor the Duke of Edinburgh like oysters. The Queen often drinks a glass of red or white wine with her meals as well as orange juice. His Royal Highness prefers gin and tonic or lager to champagne before meals or during the day."
WATCH: The foods the royals don't eat
Her Majesty's dislike of oysters makes sense considering it is widely believed that shellfish is off-limits for the Queen and Co, as it carries a high risk of food poisoning.
Former royal butler Grant Harold told Woman & Home magazine: "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 she is on an overseas tour."
Neither the Queen nor the Duke of Edinburgh like oysters
The book, compiled and edited by Paul Fishman and Fiorella Busoni, also reveals that the Queen's hosts are normally issued with written instructions from the palace before their royal visitors arrive.
READ: Royal food secrets revealed – the Queen, Prince William and more
With regards to seating at public lunches, "the host should have the Queen to his right and the Prince to his left" and "the next most important male guest must be seated to the right of the Queen". The extract also notes: "For more informal meals the palace advice is: 'The Queen and Prince Philip like to sit opposite each other across the table.'"
Dinner at Buckingham Palace by Charles Oliver, £10.19, Amazon
Darren McGrady, former chef to the Queen, has previously spoken to HELLO! about the royal family's likes and dislikes. Darren revealed that the 94-year-old monarch is not really a foodie at heart, whereas her husband Philip is more of an adventurous eater.
"The Queen never was a foodie," he revealed. "She always ate to live rather than live to eat. Prince Philip was the foodie. He'd want to try any new dishes all the time and got excited about new ingredients whereas the Queen, if we had a new recipe, she'd have to look at the whole recipe before saying, 'Yes ok let's try it.' But for the most part she stuck to the same dishes week in week out."
Former chef Darren McGrady revealed the Queen's a chocoholic!
Darren added: "She is absolutely a chocoholic. Anything we put on the menu that had chocolate on, she would choose, especially chocolate perfection pie.
"For a main course she loved game, things like Gaelic steak, fillet steak with a mushroom whisky sauce, especially if we did it with venison. For a first course she loved the Gleneagles pâté, which is smoked salmon, trout and mackerel. She loved using ingredients off the estate and so if we had salmon from Balmoral from the River Dee, she'd have that, it was one of her favourites."
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