Boil the potatoes in their skins at least two hours before dinner. Cut them in slices a quarter of an inch thick, put them in a china bowl with one or two soup ladles of hot broth or vegetable stock, and let them soak and remain tepid till dinner-time. They should so absorb the broth that they look dry. When served mix with a thin mayonnaise sauce, and surround with young lettuces previously dressed with oil and vinegar. They can be dressed with beetroot, cucumber, tomatoes, or herrings.