Peel away fears of substituting onions, shallots, scallions and leeks in recipes

Onions are a staple of cooking in almost every cuisine and season. They’re so commonplace that you probably have one variety or another around the house. But what happens when you don’t have the type called for in a recipe?

Not a whole lot, it turns out. “I think they’re more interchangeable than people think,” says Kate Winslow, who wrote “Onions Etcetera: The Essential Allium Cookbook” with her husband, Guy Ambrosino. In addition to the three bulb onions – red, white and yellow – leeks, shallots and scallions are closely related.

“Don’t let yourself be stopped” when a recipe calls for a particular onion and you only have others, Winslow advises. With adjustments, you can make it work.

In a cooked dish, red, white and yellow onions are OK substitutes for each other, Winslow says. Cooked red onions can muddy the color of a dish – when the other ingredients are alkaline (i.e. higher on the pH scale), they can turn bluish-green – but the flavor will be the same.

Raw is a different story. Sliced red onions are often served on top of sandwiches or salads. Winslow prefers yellow and white to be cooked. White onions can work as a garnish, though it will be sharper than red.

Shallots are another option for eating raw. “Shallots are a little more delicate,” Winslow says, but are a good swap for red onion, cooked or uncooked. They are more expensive than red onions, and their smaller size means you have to do more work peeling and trimming to yield the same amount (they won’t cook faster, however).

Keep that in mind before you commit to using shallots instead of red onions. Shallots don’t last as long as regular storage onions. If you come into a windfall, consider using them sooner rather than later. Their milder flavor means you can follow Winslow’s advice and use shallots for a modified version of creamed onions made with mellow pearl onions.

Scallions are great uncooked and have a fresh allium flavor. They’re interchangeable with green onions, which are immature bulb onions, says “The New Food Lover’s Companion” by Sharon Tyler Herbst and Ron Herbst. Scallions are milder than green onions. The white and green parts of scallions are edible, though recipes that use both cook the white and light green parts and use the darker greens as garnish.

Leeks, while similar to scallions, aren’t as well-suited to being eaten raw thanks to their fibrous texture. They can work well as an onion when cooked. Winslow thinks of leeks as somewhere between a scallion and a bulb onion. They have a “more subtle, refined kind of onion-y flavor” – neither the sharpness of a scallion nor eye-watering spiciness of an onion.

There’s more of an intimidation factor thanks to the extra work needed to remove the grit that accumulates between the layers (I like standing halved leeks up in a bucket of ice water to pull it out; Winslow recommends thinly slicing them and swishing and rinsing in cold water).

But don’t let that stop you from taking advantage of leeks, which often come in bunches. “I think we can revamp our thinking and remind ourselves that leeks are just an elongated bulb,” Winslow says Any of these alliums will deliver onion flavor. It’s just a matter of adjusting prep.

Take size into account. Winslow says one medium onion will yield about 1 cup chopped. That will require a different number of, say, shallots or leeks for the same volume. Think about how you will cut and cook them. Scallions are by nature smaller and thinner and will cook, and burn, faster than bulb onions.

So, no, caramelized scallions aren’t happening. If you’re using them as an onion substitute, you’ll want to cook only briefly and consider slicing them larger than you normally would. Leeks are best cooked to a soft consistency; adjust the timing or size of your slices accordingly.

Sometimes you can get away with not cooking at all. A garnish of scallions or shallots on a finished dish still gets at the spirit of onions added at the beginning. Winslow says if your meatball or meatloaf recipe first calls for cooking down onions, consider instead working raw scallions into the ground meat for a brighter taste. Ditto stuffing, where scallions and shallots can deliver that fresher flavor in addition to a pleasant crunch.

When it comes to playing around with onions, don’t be afraid to go with what’s working for you. “You suddenly might find yourself with a flavor you like more,” Winslow says. “Ninety-eight percent of the time, it’s going to be totally fine.”