The onion is a member of the allium family (along with garlic, chives, shallots and leeks). Though to have originated in Central Asia, onions are now the most universal seasoning used. Most onions are actually biennials and will go to seed in the spring if not harvested the prior season. Onions come in a variety of colors including shades of white, yellow, red, and purple. White and purple onions tend to be milder and sweeter, while tan-skinned storage onions are more potent. When properly cured and stored, many bulb onions will store will through winter. Onions are a good source of vitamin C, dietary fiber, and folic acid.
Bulb onions can store in a cool, well ventilated place for several months (warmth and moisture will encourage sprouting). Cut onions can be stored in an airtight container in the refrigerator for a few days.
To avoid crying while chopping onions, chill in the refrigerator or cut under running water. Eat raw or cook briefly for a stronger flavor, or cook longer for a more mellow flavor. Long cooking or roasting sweetens and caramelizes onions. Onions are incredibly versatile – use in soups, stews, casseroles, omelets, salads, pizza, sandwiches, etc.
1 ½ - 2 pounds onions (6-8 medium), halved and thinly sliced or chopped (5-6 cups)
2 tablespoons extra virgin olive oil or butter, plus more as needed
Salt and freshly ground black pepper
Put onions in a large skillet over medium heat. Cover and cook, stirring infrequently, until onions are dry and nearly sticking to the pan (about 20 minutes). Take off cover, stir in oil and a large pinch of salt, and turn the down to medium-low heat. Cook, stirring occasionally, until the onions are cooked as you like them, adding just enough additional oil or butter to keep from sticking but without getting greasy. Onions will be ready immediately or after up to an additional 40 minutes, depending on your preference. Taste and add pepper, and more salt if desired. Serve hot or at room temperature. (Recipe from How to Cook Everything Vegetarian: Simple Meatless Recipes for Great Food by Mark Bittman.)