The pleasures of a hearty, warming bowl of soup can hardly be overstated. Replete with vegetables, beans, grains, or meats, few foods are more gratifying to make -- or easier. Soups require almost no culinary skill, no elaborate equipment. They store well, and most of them taste even better prepared in advance. Judy Knipe, coauthor of SPA FOOD and NEW SPA FOOD, knows how traditional foods can be transformed into elegant meals that satisfy the way...