Potato Pete was no preacher of austerity. In the midst of deprivation, he promised indulgence, happily surrendering himself into the hands of cooks, ready to be boiled, steamed, mashed, roasted, baked, fried, scalloped, deviled and stuffed. The British historian Eleanor Barnett, whose smart, high-spirited account of food waste and preservation over the centuries, “Leftovers,” came out this year, was particularly curious about his recipe for teatime scones: It was a surprising treat given that at some points during the war, ice cream was banned — the Ministry of Food suggested, crushingly, eating carrots instead — and Britons were allotted as little as eight ounces of sugar a week. (Not to mention, and perhaps more devastating for the British soul, just two ounces of tea.)