you can give your onions a quick soak in cold water to reduce their sharpness.
GREEN ONIONS
LEEKS
The white root ends on this allium are what we eat (the sturdy green leaves are fibrous). Leeks’ many thin layers trap dirt, so to clean them, cut off the root end, then rinse under running water. Usually sliced thin, leeks have a mild, buttery onion flavor when cooked.
SPRING (SALAD) ONIONS
Sold by the bunch, these onions have white bulbs attached to their long green stems. They’re not just large or overgrown scallions, but fresh, young bulb onions picked before maturity. They have a mild, clean flavor and are entirely edible, including their stems. Peak season is May through June.
SCALLIONS
Slender scallions, also called green onions, are often mistaken for very young spring onions. In reality, they’re a distinct variety that will never be bulbous. Use both the white and green parts, unless a recipe specifies otherwise. While the white parts can be cooked, the green stems are best when used raw — they can burn quickly.
CHIVES
Although usually used like an herb, chives are actually classified as an allium. The tender green tubular stalks have a fresh, delicate onion flavor without any of the heat. They’re best used raw or added at the end of cooking so they hold their color.
BULB ONIONS
YELLOW ONIONS
These are the most versatile and commonly used onions
(88 percent of U.S. onion crops are yellow). They’re very pungent when raw, but the heat disappears when cooked. Fresh varieties with thin skin are milder than the storage onions with thick skin.
WHITE ONIONS
They’re just as pungent as yellow onions, but white varieties tend to have a sharper, cleaner flavor, and a slightly shorter shelf life. Mexican cuisine uses white onions almost exclusively, primarily due to availability and tradition.
RED ONIONS
These onions tend to be a little less pungent than white or yellow varieties and their rings are often irregularly shaped. They’re best used raw so their purplish-red hue stays vibrant. Red onions turn a muddy color when sautéed, but hold their color when grilled or broiled.
SHALLOTS
Thin-skinned shallots grow in clusters. With their fine layers, they’re like small, tender onions that have a more delicate flavor and texture, and are also more expensive. Use raw, or cook them for subtle oniony flavor.
PEARL AND BOILING ONIONS Tiny pearl onions (about 1 inch in diameter) aren’t baby onions, but their own mature variety. On the other hand, larger boiling onions (about 2 inches in diameter) are actually small storage onions. Both are available in yellow, white, and red.