onions - baking tin
Onions are a good source of vitamin C, fiber, and antioxidants including quercetin and anthocyanins (particularly in red varieties). They contain prebiotic compounds that support digestive health.
About
The onion (Allium cepa) is a bulbous vegetable belonging to the amaryllis family, native to Central Asia and cultivated worldwide for thousands of years. It consists of concentric layers of fleshy, modified leaf bases surrounding a central stem, with papery outer layers that range in color from golden-yellow to red or white depending on cultivar. The characteristic pungent flavor derives from volatile sulfur compounds (thiosulfates) that are released when cell walls are damaged during cutting or cooking. These compounds break down with heat, transforming the onion's sharp bite into sweet, caramelized notes. Major varieties include yellow onions (the most versatile and commonly used), red onions (milder and sweeter, with anthocyanin pigmentation), and white onions (more delicate in flavor).
Culinary Uses
Onions serve as foundational aromatics in countless cuisines, typically sautéed or caramelized as a base for soups, stews, sauces, and braises. They are essential to French mirepoix, Italian soffritto, Spanish sofrito, and many other culinary traditions. Raw onions add sharp, fresh notes to salads, salsas, and sandwiches. Caramelized onions develop deep umami complexity when cooked slowly over low heat, making them ideal for soups, gratins, and toppings. Roasted whole or halved onions become sweet and tender. Pickled onions provide acidic counterpoint in various cuisines. The green tops (scallions) and milder spring onions are used fresh as garnishes and in stir-fries.