What is a spring onion? At first blush, that’s a muddled question of variety, size and time of year. Elizabeth Schneider, in Vegetables from Amaranth to Zucchini, explains:
Taxonomically, a green onion is the same species (Allium cepa) as a common onion and a “sweet” onion. Or it is a different species. Or it is a cross of the two. In case you don’t think this scientific description is helpful, just try finding a common one…
Later, she clarifies:
The terms spring onion and salad onion are more likely to describe a later stage of green onions (or scallions), green-topped with more developed bulbs.
In other words, what we call spring onions are usually young onions, more mature than a straight green onion or scallion, less mature than the bigger round things we call onions. Like Schneider says, spring onions might be any variety (or a cross between different ones). The ones at my Whole Foods right now are young and sweet, straight from Vidalia.
More importantly, spring onions are fresh, tender, mild and redolent of new growth. They’re delicious raw, thinly sliced and tossed in salads. When sautéed or braised with other spring vegetables and fresh herbs, they add earthy onion background flavor without overpowering the dish.
Recipe: Fingerling Potato And Spring Onion Salad With Mustard Dressing (Cookthink)
Recipe: Chicken In Parchment With Mushrooms, Spring Onions And Zucchini (Cookthink)
Recipe: Braised New Potatoes With Spring Onions And Chives (Cookthink)
Reference: What’s the difference between a green onion and a scallion? (Cookthink)