Carl Sandburg at one time stated that life itself is like an onion: "It has a bewildering number of layers; you peel them off, one by one, and sometimes you cry."
The onion gets its name from the Latin "unio", derived from the French "oignon" and the English "unyun". It's one of the most important flavoring ingredients in kitchens throughout almost every culture worldwide. In fact, onions were one of several vegetables the Hebrews complained to Moses about missing when leaving Egypt for the Promised Land (as well as cucumbers and garlic - see Numbers 11). Believe it or not, the gorgeous Easter lily and the smelly onion are close cousins, both being members of the lily family. In ancient Egypt, it was a custom for those taking an oath to raise one hand and put the other on an onion.
It is known that Egyptians placed onions in their tombs about 3500 years ago. Onions were possibly a part of the mummification process because of their spiritual significance and because their size replicated the human eyeball. Ancient Egyptians revered the onion so highly that there was actually an onion cult (Romans 1:25). Even though America loves the onion, it doesn't rate quite this high these days, although it is hard to imagine favorite foods without the flavorful onion.
Yellow onions are one of the most popular traditional varieties of onions. They are used mostly for soups, stews, sandwiches, hamburgers, and salads. Many other prepared dishes are best with this onion too, such as dips, relishes, salsas, and sauces. To prepare, cut onion in half, trim ends and peel. If you only need half an onion, the other half will keep best left with the skin on, wrapped in plastic, and refrigerated. You don't need to refrigerate whole onions - just store them in a cool dry area.
Red onions are just about as common as the yellow, also being grown worldwide, and are used in salads or served in dishes raw, grilled, or roasted. The red onion is also known as sweet Italian onion, Italian red onion, Creole onion, and red torpedo onion. They have a bit milder flavor than the yellow onions.
Sweet onions are also very common, which are usually just hybrids of the yellow onions. Vidalia onions are very mild, succulent, and crisp while being one of the sweetest onions on the market. They have only been growing since the 1930's, and it wasn't until 1986 that the Vidalia onion earned its legal status to define the production boundaries for its growing region in Vidalia, Georgia. Share and find some good recipes for these here: http://www.christianchefs.org/ubb/Forum4/HTML/000065.html
Many other varieties of onions exist as well; many are hybrids, some are not. The most popular of these are pearl onions, spring onions, torpedo onions, cipoline onions, and green onions.
Tearing up from onions is produced through cutting layers of their skin expelling a tearing chemical, pyruvate. There have been many suggestions how to prevent tears when slicing onions. Some say to hold the onion under running water while peeling and cutting, wear goggles or simply hold your breath. Others say to freeze the onion for twenty minutes or to chop them on the stove with the exhaust fan on high. If you're not very keen on those "emotional" moments, share what works for you, and find how not to tear up here: http://www.christianchefs.org/ubb/Forum2/HTML/000128.html
Studies show that many health benefits are credited to onions, which include lowering blood pressure and cholesterol levels. A substance that interferes with the formation of blood clots is also found in onions. Onions provide carbohydrates, fiber, protein, vitamin C, calcium, iron and potassium. One medium onion contains about 60 calories. Onions are antioxidants that combat a variety of diseases, including some forms of cancer. Yellow onions are a good source of quercetin, a potent antioxidant that aids the immune system as an antibacterial, antifungal, anti-inflammatory and antiviral agent. It is also beneficial against hay fever, diabetes, asthma and chronic bronchitis.