Onions are rare food that can be sweet, savory, pungent and aromatic all at the same time. Onions are what make food good, making it enjoyable and taste good.
Onions don’t contribute much in the way of nutrition. The odd vitamin and mineral, sure, but nothing that isn’t far more abundant in other commonly available foods like rice or broccoli or they are not functionally necessary for any recipe.
If we consider eggs, the culinary arts would look much different without eggs. Things like cake or custard or hollandaise sauce, and many other basic preparations simply wouldn’t work.
If you took away onions from recipes they would still work, they just wouldn’t taste so good.
Onions are a Culinary Luxury
Thus onions are a luxury. And yet are cheap and plentiful and will grow just about anywhere.
Onions can be roasted, grilled, pickled, caramelized, battered and deep-fried, sliced thinly or chopped and served raw in salads, sandwiches, dips, or as a garnish for tacos, making them among the most versatile and ubiquitous ingredients in the culinary arts.
Onions make up a third of the classic mirepoix, a basic mixture of onions, carrots and celery used to enhance the flavor of soups and stocks and sauces, and which appears under different names in different cuisines.
Here are a few of the most common types of onions, and what they’re good for.
The workhorse, the staple, the everyday brown beauty, yellow onions are suitable for any conceivable use, other than perhaps as a garnish for your martini. You could easily live a rich and fulfilling life even if this were the only onion you ever tasted.
Its heavy brown parchment skin surrounds ivory white flesh with a strong, sulphury, pungent flavor and aroma. If a recipe says onion without specifying what type, it’s assumed to be a yellow onion. Use them for making French onion soup.
Larger and slightly flatter than yellow onions, with lighter colored, less opaque skin, sweet onions contain extra sugar, making them good for caramelizing. Their larger size and sweeter flavor makes them ideal for making onion rings. Sweet onion varieties include Walla Walla, Maui, Vidalia, as well as others with the word “sweet” in the name.
White onions have a papery white skin, and their flavor is milder and sweeter than yellow onions, making them good for serving raw in fresh salsa or homemade guacamole.
Sweet and mild enough to be eaten raw, both the exterior skin and the flesh of red onions are a deep magenta color, which makes them particularly good additions to salads or anywhere else a splash of color will enhance the appearance of the dish. I love to use red onions in salads and on sandwiches and burgers.
Shallots are small, brown-skinned onions with purplish flesh, and their bulbs are made up of multiple lobes, a little bit like the way garlic bulbs are divided into individual cloves.
Pungent and garlicky, shallots are weirdly unappreciated in the United States — at least based on how infrequently they appear in recipes, and the sort of careless disarray with which they tend to be displayed at the supermarket.
Shallots are possibly the most sublime onion. They impart a very intense flavor, and because they’re smaller, composed of thinner layers, they can be minced very finely and used in salad dressings and sauces. They’re lovely to roast, however. Peel and halve them, and toss them in the bottom of the pan when you’re roasting a chicken, and you’ll see what I mean.
Green onions are immature onions that have not yet formed a bulb, or only partially. The entire plant is usually used, including the tall green shoots, and they make a wonderful garnish for soups, omelets, tacos, as well as color and crunch. They go by other names, including scallions, spring onions, cebollitas (in Spanish), salad onions, and even — shallots!
They get around the confusion by calling shallots “French shallots,” a workaround which is nevertheless wholly unnecessary since shallots and scallions already have perfectly good names. And going around renaming things willy-nilly is bad enough. But intentionally giving one onion the name of a completely other type of onion seems to me to be the height of recklessness.
Leeks are a truly marvelous vegetable, and also sadly underappreciated. Shaped like overgrown scallions, leeks are lovely in soups and sauces, and one of my favorite ways to prepare them is à la gratinée — baked and topped with seasoned breadcrumbs and Gruyère cheese. Baking the leeks mellows their flavor and softens them. This potato leek soup is another terrific way to use them.