Photo by Scot Nelson on Wikimedia Commons (CC0 1.0)

* 1 onion

ProduceYear-round; fresh onions peak in late summer through fall, while storage varieties remain available throughout winter and spring in most temperate regions.

Onions are rich in vitamin C and quercetin, a powerful antioxidant flavonoid with anti-inflammatory properties. They are low in calories and provide dietary fiber, particularly when the skin is consumed.

About

The onion (Allium cepa) is a bulbous biennial plant in the amaryllis family, native to Central Asia and cultivated worldwide for millennia. The edible portion consists of concentric layers of fleshy leaves that form a papery-skinned bulb, typically ranging from 2 to 6 inches in diameter depending on variety. Onions are characterized by their pungent, sulfur-containing compounds that create their distinctive sharp taste and tear-inducing aroma when cut. The flavor profile ranges from intensely acrid and spicy in raw form to sweet and mellow when caramelized through long, slow cooking. Major varieties include yellow onions (the all-purpose standard), white onions (milder and crisper), red onions (sweeter with purple pigmentation), and sweet varieties such as Vidalia or Walla Walla.

Culinary Uses

Onions are foundational aromatics in virtually every global cuisine, serving as a base flavor layer in stocks, soups, stews, and sautéed dishes. They are used raw in salads and salsas for crispness and bite, caramelized slowly for deep sweetness in French onion soup and confit preparations, grilled or roasted for mellow complexity, and pickled for acidity and crunch. In Indian cuisine, onions are essential to curries; in Mexican cooking, they anchor salsas and braises; in French cooking, they form the mirepoix base; and in Middle Eastern cuisine, they are central to kebabs and stuffings. Proper technique involves cutting to consistent sizes for even cooking and understanding how heat transforms their flavor from pungent to progressively sweeter.

Forms & Preparations

Whole/unpeeled — Roasted whole in skin until caramelized, then flesh squeezed from papery exterior for a sweet, mild base or accompaniment.
Diced — Cut into roughly 1/4-inch cubes, the standard form for mirepoix, soffritto, and building flavor bases in soups and stews.
Sliced — Cut crosswise into rings or half-moons, used for caramelizing, raw salads, or quick-cooking in stir-fries.
Julienned/matchstick — Cut into thin, uniform sticks for faster cooking, fine texture in stir-fries, or delicate raw applications.
Minced — Finely chopped, used for salsas, dressings, and dishes requiring even, quick incorporation of onion flavor.
Caramelized — Slowly cooked over low heat for 45 minutes to several hours until deeply golden and sweet, used for French onion soup, burgers, or confit preparations.