During the Great War, large numbers of ordinary people traveled abroad for the first time, eating and drinking French and Italian food along the way. This, plus the determination of governments afterward to emphasize shared values and preserve peace, led to a definite postwar expansion of culinary influences into mainstream British cooking. Books on Italian cookery had been published before, but now books such as The Gentle Art of Cookery, by Hilda Leyel and Olga Hartley, contained lots of recipes for slightly exotic-sounding ways to transform boring British vegetables. British vegetable cookery was centered largely around boiling, mashing, and gratins, with sauces usually based on butter and cream. Although vegetables served in this way can be sublime, the cooking times given in books suggest they were habitually overcooked. At Downton, many of the upstairs dishes are served with watercress or spinach, which gives the plates color but, more importantly, gives the cast something practical to eat in front of the cameras when they are repeating scenes many times over. The triangular shape of the croutons is traditional, but you can vary it as you wish.