Lunch takes no more than an hour. Then they’re up and, after coffee, head straight outside. Unlike many of her subjects, the Queen does not have a Sunday afternoon nap. Prince Philip, with his love of cooking, has found a new passion – foodie TV shows – and the Queen makes a great joke of teasing him about his craze for watching all the cookery programmes. Mary Berry is a favourite. ‘The Duke of Edinburgh understands cooking,’ Berry says. ‘I’m very lucky to have had lunch with the Queen. I was seated next to the duke – a delightful man – who talked about barbecuing. He was saying that he took his game birds at Sandringham and stuffed them with haggis but put more breadcrumbs in to absorb the fat . . . you knew he knew what he was talking about.’

Prince Philip certainly knows what he is talking about when it comes to food and cooking. In the days when he used to travel abroad frequently, he would always return with some new dish he urged the Buckingham Palace chefs to try. They dreaded the sound of his purposeful footfall as he made his way to the kitchens to bark out instructions. If the dish didn’t arrive at the table exactly as he remembered it, then there would be another visit to the kitchen and a searching discussion to find out what went wrong. Philip always explained what was not quite right and exactly how it could be done in the future. Of course, Philip doesn’t just preach, he practises and, according to those who have sampled his food, he is no mean cook.

One of his most ambitious dishes used to be snipe which, after shooting it at Sandringham, he plucked, cleaned and prepared himself. He arranged to be called especially early in the morning so he could get the snipe ready before breakfast. While he was out on his day’s duties, the snipe remained in the larder almost under armed guard and when he returned in the evening he quickly changed and set about cooking the bird. Philip has his own cookbook with his favourite recipes he has ordered for himself. One was a casserole of pigeon, cooked according to a Swedish recipe, and he would go out a shoot a brace just because he fancied them.

Philip liked to cook breakfast for himself and the Queen and was famous for his glass-topped electric frying pan, which had to travel everywhere with him. Omelettes were his speciality and he was good at producing quick light supper snacks which he and the Queen enjoyed after the staff had been dismissed. Scrambled egg, smoked haddock, kidneys, mushrooms and bean shoots with mushrooms and chicken livers were favourites, but nothing is as good to him as open-aired barbecuing, as Mary Berry testified.