· 1 large onion

The onion (Allium cepa) is a bulbous plant belonging to the Amaryllidaceae family, native to Central Asia and cultivated worldwide for millennia. The edible bulb consists of concentric layers of fleshy, translucent scales wrapped in papery outer skin, ranging in color from white to yellow to deep purple depending on variety. Onions possess a distinctive sharp, pungent flavor when raw due to volatile sulfur compounds, which mellow and sweeten considerably when cooked through caramelization and the breakdown of sulfurous compounds. Common cultivars include yellow onions (most versatile), white onions (milder, crisp), red/purple onions (sweeter, used fresh), and sweet varieties such as Vidalia and Maui.

Onions are fundamental aromatics in virtually all savory cuisines, serving as a flavor base for soups, stews, sauces, and braises. They are sautéed, caramelized, grilled, roasted, pickled, and eaten raw in salads and salsas. In French cooking, they anchor the mirepoix; in Asian cuisines, they provide umami depth to curries and stir-fries. Raw onions add sharp bite to sandwiches and ceviche, while long, slow cooking transforms them into sweet, jammy condiments ideal for burgers and gratins. Yellow onions are preferred for cooking; white and red varieties excel in fresh applications.