Spatulas toss food high into the air above the pot. Tie a tea towel around your head and make noises like a samurai warrior. You'll have your family or friends laughing hysterically, but chances are you won't be cooking effectively. Speed and control are the keys to a successful stir-fry. The ancient Chinese invented stir-frying as one of their more than 50 methods of food preparation. However, many recipes now use the technique for many non-Asian dishes. It's quick, requires little fat, and leaves food with a toothsome texture we enjoy today. While it's possible to adapt many recipes to stir-frying, oil rather than butter should be used. Dairy solids in butter burn at a very low temperature--about 250F--so it can only be added as a flavoring agent once food is cooked. Oil, on the other hand, doesn't begin to smoke until more than 400 degrees, so it's a better choice. Another key principle: Never place too much food in a wok or skillet at a time. Food must be able to be seared all over, without steaming from being buried under a layer of food. Stir-frying itself is a very quick process, so the food must be sitting in bowls or dishes placed within arm's reach, ready to be cooked. Cut all the pieces the same size, have your seasonings at hand, and make sure that any partial cooking of vegetables--such as blanching broccoli or carrots--is complete. If your grocery store has a salad bar, it can save a lot of preparation time. Go through the salad bar and measure out just the ingredients needed for a recipe. Place the wok or skillet over a high flame, and heat it very hot. Listen for the sound of sizzles. If a few drops of water evaporate immediately, the pan is ready. Add the required amount of oil to the pan, and swirl it around gently to coat all sides. At this point, it's time to add the food, and keep it moving in the pan. If stir-frying in a wok, use a wire mesh spoon designed for the job. If stir- frying in a skillet, use a spoon that will reach to all places on the bottom, and with which you can keep food moving. It's important to add ingredients in the order given, and stir constantly. In some recipes, liquid is added and the pan is covered for a brief time. In other recipes, it's fry and eat. Whatever the method--wok or skillet--you can stir-fry dinner in less time than it takes to watch a commercial on the evening news.