Soups Few people, it seems, eat soup any longer. In our diet conscious lives, many diners save their calorie-allowance for the main dish—but a clever gourmet chef never overlooks the possibilities in soup. Of all the packaged foods available today, soup is probably the easiest to trick up into a replica of grandmother's stockpot.  Almost anything can be used for soup—and almost any of these things is available either in tins or powders.  Hot soups replace an appetizer on a cold night; chilled soups, flanked by a chefs salad, are just right on a warm evening. Hearty soups, full of meat and vegetables and accompanied by plenty of garlic bread, are superb for Sunday nights, and for the lucky people within reach of a country garden, fresh vegetable soups are memorable for a quick supper after a day at the beach.  1. For richness of taste in cream soups, use milk in place of water—or cream in place of milk—in the amounts directed. 2. An authentic petite marmite takes time—but onion soup makes a good substitute. 3. Fresh vegetable soups require only cream and milk, plenty of butter, and almost any lightly cooked fresh vegetable . . . 4. For emergencies, combine two cans of almost any con ceivable condensed soup, dilute with milk or water-and-wine,and create a satisfying dish. For a fancy effect, hot soup should be served from a tureen at table—and the buffet dishes warmed by a candle are so impressive that people who thought they didn't like soup will eat two plates full!