each medium onion

The onion (Allium cepa) is a bulbous perennial plant of the amaryllis family, native to Central Asia and cultivated worldwide for its pungent, layered underground bulbs. The typical culinary onion is characterized by papery, tan, red, or white outer skin layers surrounding concentric rings of fleshy, white to pale yellow tissue. Common varieties include the yellow onion (most pungent, best for cooking), red onion (milder, sweeter, preferred raw), and white onion (sharp flavor, common in cuisines from Latin America and Asia). A medium onion typically weighs 150–200 grams with a diameter of 2.5–3 inches. The flavor profile ranges from sharp and sulfurous when raw to mellow and caramelized when cooked, due to chemical reactions involving sulfur compounds and reducing sugars.

Onions are foundational aromatics in virtually all savory cooking traditions, serving as a flavor base for soups, stews, curries, braises, and sauces. They are diced or chopped and sweated in fat to release sweetness and umami before other ingredients are added. Raw onions are thinly sliced or diced for salads, sandwiches, and pickled preparations. Caramelized onions, produced by long, slow cooking over moderate heat, develop deep sweetness and are used in French onion soup, burgers, and side dishes. Roasted whole onions become creamy and mild. Onions also function as a primary ingredient in crispy fried onion garnishes, onion rings, and are essential in condiments such as salsa and relish.