Spring onions are comprised of small round to oval bulbs, averaging 2 to 5 centimeters in diameter, attached to a straight, layered stalk of overlapping leaves. The bulbs are smooth, firm, crisp, and succulent, found in bright white to red hues, depending on the variety. There may also be a cluster of fresh, flexible, and fine tan roots attached to the bulb's base. The slender, tubular leaves have a stiff, thick, and crunchy consistency and are hollow, bearing dark green hues on the edges and lightening to a pale green tone near the bulb. Spring onion bulbs contain sugars and are absent of the gases developed in more mature bulbs, creating a sweet and mild, mellow flavor. The leaves have a stronger taste and contribute herbaceous, pungent, and grassy nuances.
Spring onions contain vitamin A to maintain healthy organ functioning; vitamin C to strengthen the immune system, and vitamin K to promote faster wound healing. The onions also provide calcium to protect bones and teeth; potassium to balance fluid levels within the body; antioxidants to reduce inflammation, and other nutrients, including phosphorus, magnesium, and copper.
Spring onions have a fresh, sweet, and subtly pungent flavor well suited for both raw and cooked preparations. The bulb and leaves are edible, and the leaves will contain a stronger flavor than the mild bulb. When used fresh, spring onions can be thinly sliced and tossed into salads, layered onto sandwiches, or stirred into grain bowls and slaws. Chefs also favor the mild pungency of homemade aioli and for pairing with soft cheeses, dips, and creamy spreads on appetizer platters. In addition to fresh preparations. Spring onions can be lightly cooked and are commonly simmered, roasted, grilled, or sauteed. The onions can be stirred into soups and stews, baked in casseroles, used as a topping over pizza, stir-fried with other vegetables, or sprinkled over egg dishes. Spring onions pair well with other spring vegetables, including asparagus, sweet peas, young lettuces, mushrooms, and radishes, citrus, potatoes, vinaigrettes, cream-based sauces, and meats such as poultry, turkey, and fish. Whole, unwashed spring onions will keep for 4 to 5 days when stored in a perforated bag or plastic bag with paper towels in the refrigerator's crisper drawer. If the onions are used within 1 to 2 days of purchase, they can also be stored at room temperature away from direct sunlight.
Spring onions are available year-round.