½ onion

The onion (Allium cepa) is a bulbous biennial herb of the amaryllis family, native to central Asia and cultivated worldwide. It consists of concentric layers of leaf bases that form a papery-skinned bulb, ranging in size from small pearls to large Spanish varieties. The flesh ranges in color from white to yellow to red, depending on cultivar, with a texture that transitions from crisp when raw to tender and sweet when cooked. Flavor intensity varies dramatically by type and cooking method—raw onions deliver sharp, pungent notes from volatile sulfur compounds, while long, slow cooking converts these compounds into deep, caramelized sweetness. Major cultivars include yellow storage onions, sweeter Vidalia and Walla Walla varieties, crisp red/purple onions (Allium cepa var. aggregatum group), and white onions favored in Latin American and Asian cuisines.

Onions function as a foundational aromatic in virtually all savory cuisines, forming the flavor base (mirepoix in French cooking, soffritto in Italian, recaito in Puerto Rican) for stocks, soups, and braises. Raw onions add sharp bite to salsas, salads, and sandwiches; sliced and caramelized, they become a sweet condiment for burgers and savory tarts. Pickled onions serve as a palate-cleansing accompaniment in Indian and Southeast Asian meals, while grilled or roasted whole onions complement grilled meats. Diced small, they meld into sauces and braises; sliced thin, they feature in French onion soup or become crispy fried toppings. The entire plant—bulb, green shoots (scallions), and flowers—is edible across different growth stages.