Midnight supper, perhaps for New Years Eve or after the show, can be exotic in a hurry. The foods are sliced ahead, the sauces made, then all stowed in the refrigerator. When guests are hungry, the hostess simply heats the broth and sets out the makings. Genghis Khan hot pot is another name for this Chinese specialty. Or maybe youve seen it on restaurant menus as volcano soup. We show an honest-to-goodness Mongolian cooker with a charcoal chimney in the center, but any chafing dish or electric skillet will do as well. Whats cooking. Everything on the tray is raw, of course--chunks of eggplant, crosscut strips of sirloin, halved mushrooms, thin slices of chicken breast, squares of Chinese cabbage, shucked shrimp. Fresh spinach to simmer along with the other foods is ready in the big red bowl. The broth is chicken bouillon that boasts a faint overtone of ginger. Individual bowls of fluffy rice are served at the same time as Hot Pot. The how-to. You pick out a few choice tidbits at a time and drop them from chopsticks, bamboo tongs, or fork into the lazily bubbling broth. In a few minutes, fish them out to dip into zesty sauces on your plate, like Peanut or Red Sauce, Chinese Mustard or Ginger Soy. Traditionalists poach eggs in the broth when it has taken on subtle flavor from the foods that have simmered in it. At the very last, the hostess may ladle the broth as a soup. Its delicious! Dessert? Skip it, or serve a fruit bowl and candied ginger with coffee or tea. Etiquette: Use one set of chopsticks for cooking and fishing out morsels from Hot Pot, use a second set for eating. If only one set is provided for each guest, simply reverse your chopsticks (large ends down) when you cook or help yourself to food. Oriental Hot Pot Chinese Mustard Ginger Soy Peanut Sauce Red Sauce Hot cooked rice Shortly before cooking time arrange the meats and vegetables on large tray or platter; use a bowl for spinach. Set out dunking sauces. Provide Bamboo tongs, chopsticks or long-handled forks as cooking tools for guests. Heat chicken broth in electric skillet or chafing dish (or use Mongolian cooker-- directions follow). Add bouillon cubes to hot broth and stir to dissolve; add monosodium glutamate and ginger. Heat to simmering. For cooking have broth barely bubbling. Each Guest picks up desired foods with chopsticks or whatever, drops them into the bubbling broth. When his tidbits are cooked, he lifts them out and dips into the sauces on his plate. Serve with rice. Makes 4 servings. To use Mongolian cooker, fill chimney of cooker with charcoal and add charcoal starter. Pour cold chicken broth into cooker. Cover cooker, then light charcoal. When broth is hot, continue as above.