How many people can you think of who are instantly recognisable by one name? Oprah. Bono. Um, Lassie? And Delia of course. Dearest Delia, who likes to make sure we know how to boil water before letting us move on to putting eggs in it. At least, she did until she discovered that you can buy them ready-boiled at Waitrose. Since Masterchef we all know that anything more than that is 'seriously tough', though ...