Onions may be white, yellow, or red, and pungent, mild, or sweet — the variety is astonishing.
Sweet onions, including Bermuda, Maui, Vidalia, and Walla Walla, are juicy and have a less pungent flavor.
On the smaller side are pearl or boiling onions, cipollini, and shallots. Pearl onions are up to the diameter of a quarter and are best for boiling, braising, and stewing; their small size allows them to cook through whole. Cipollini can be used the same way as pearl onions, and their flattened shape adds an interesting look to any dish. Shallots range greatly in size, and can be cooked whole or used chopped like onion.
Scallions and spring onions with green stems attached are generally milder in flavor and softer in texture. Their small size makes them a wonderful garnish. Scallions in particular are fantastic to use raw as a flavorful oniony garnish on salads and in soups, dips, and other dishes; they’re also good grilled.
Buying and storing Onions and shallots should be firm and tightly covered in at least one layer of shiny tan-to-yellow or deep red skins; the outer skin of white onions is more papery. An acrid onion aroma before peeling is an indication of a damaged or rotting onion; such onions should be avoided, as should sprouting onions. Store onions and shallots in a cool, dark, airy spot or in the refrigerator for weeks. Store scallions and spring onions in the refrigerator, up to several days.
Preparing Cutting an onion results in the combination of enzymes that are stored separately in the onion, which then creates a volatile sulfur compound. When this makes contact with the moisture in your eyes, it forms a weak solution of sulfuric acid — hence the burning sensation. If you’re peeling and chopping a lot of onions or shallots, you might consider wearing goggles to prevent crying. Cooking deactivates these enzymes, so after you peel the onion (do this without cutting into it), drop it into boiling water for 30 to 60 seconds, drain, and then cut. Water absorbs the gas, so you can also rinse the peeled onion before cutting.
Leave the root end on onions or shallots you will cook whole; they’ll stay together better. For shallots, break the cloves apart and remove the dry skins; trim the stem end and slice or chop as you would an onion.
Best cooking methods Sautéing, roasting, grilling
When is it done? When very tender but not quite falling apart
Other vegetable you can use Leeks