That’s true—if you knew Her late Majesty’s favorite dish was rotisserie chicken, for example, why would you ever want to serve her anything else at an official engagement? And, because of the repetition, it would quickly not become her favorite dish.
The royal family has quite a few rules around food, and, while the Queen never let us in on her favorite meal, the Princess of Wales has been open in the past about not only the dishes she prefers but also how much she enjoys cooking at home with her children Prince George, Princess Charlotte, and Prince Louis.