Photo by Scot Nelson on Wikimedia Commons (CC0 1.0)

onion or several scallions chopped

ProduceYear-round availability; fresh scallions peak in spring and early summer, though cultivated year-round in temperate climates. Storage onions are harvested in late summer and autumn and remain shelf-stable for months.

Onions are a good source of vitamin C, dietary fiber, and quercetin (an antioxidant flavonoid); both onions and scallions contain prebiotic compounds that support digestive health.

About

The onion (Allium cepa) is a bulbous vegetable belonging to the Amaryllidaceae family, native to Central Asia and now cultivated worldwide. The bulb consists of concentric layers of fleshy leaves arranged around a central stem, with a papery outer skin ranging from golden to red or white depending on variety. Common culinary varieties include yellow onions (mild when cooked, pungent when raw), red onions (sweeter with purple-red flesh), and white onions (crisp and slightly sweet). The characteristic pungent flavor derives from sulfur compounds (particularly thiopropanal S-oxide) that are released when cell walls are ruptured during cutting, and these compounds mellow significantly during cooking through caramelization and breakdown.

Culinary Uses

Onions serve as a foundational aromatic in countless cuisines, providing umami depth and flavor development through various cooking methods. They are sweated or caramelized as a base for stocks, stews, soups, and sauces across European, Asian, and Latin American traditions; diced raw in salsas, salads, and relishes; and pickled for condiments. Scallions (Allium fistulosum), also called green onions or spring onions, have a milder onion flavor with edible green tops and white bases, used fresh as garnish, in stir-fries, or mixed into dips and composed dishes. Both forms are essential to flavor-building techniques and pair well with virtually all savory ingredients.

Forms & Preparations

Whole bulbs — Unpeeled onions used for roasting, grilling, or storage; can be caramelized whole or quartered.
Diced or chopped — Cut into various sizes depending on cooking method; smaller pieces integrate faster in stocks and sauces, larger chunks remain distinct in braises.
Sliced (rings or half-moons) — Thin slicing for sautéing, caramelizing, or raw use in salads and sandwiches; thicker slices hold shape better when grilled.
Minced or grated — Very fine pieces for emulsions, marinades, and dishes requiring rapid incorporation or texture-binding.
Caramelized — Long, slow-cooked in fat until deep brown and intensely sweet; used in French onion soup, gravies, and condiments.
Fresh scallions (whole or chopped) — Both white and green portions used fresh as garnish, in raw preparations, or briefly cooked in stir-fries to retain mild onion flavor and textural contrast.