This is very self-indulgent and wonderful. It must have been served to Picasso and Hemingway, who were regular guests of Alice B. Toklas and her companion Gertrude Stein in pre-war Paris. The recipe is as she wrote it.
‘Bake four large potatoes, peel them and put through the food mill. While the potatoes are still hot, add two cups of butter and one teaspoon of salt. Undoubtedly 1lb of butter is extravagant but try it once.’