For some odd reason, an onion soup mix was the #1 most captured recipe on Cook’n sitewide last month. It made me scratch my head for just a second, but honestly I get it. Onions are delicious and affordable, and onion soup is one of the most famous dishes in the world.

Onion soup is often characterized by the following:

• Beef broth
• Luxuriously caramelized onions
• Wine and/or brandy or cognac
• Delicious croutons
• Melted cheese

You can get as fancy as you want with your herbs and spices, but before then you’d better decide exactly how you want to tackle the above elements.

History of Onion Soup

Onion soup has its roots in the Roman empire. It was, and always has been, a peasant dish because onions were cheap and easy to grow. However, in the 17th and 18th centuries, onion soup became a staple in France, often linked to King Louis XV’s court. Despite those lofty heights, the soup was associated with market workers in Paris in Les Halles Market, where it was served as a restorative breakfast for early-morning workers.

In the mid-20th century, America’s resurging interest in French cuisine (spurred by Julia Child and the likes) brought French onion soup into vogue in the States. Finally, here we are today.

French onion soup somehow bridges the gap between peasant food and haute cuisine. It’s incredibly simple to elevate it from an end-of-the-day comfort meal to a MIchelin-starred bowl of ambrosia just by tweaking some parts. But at the end of the day, it all comes down to the onions.

Here’s where I suddenly flip the script on you because this isn’t actually an article about onion soup. It’s an article about onions.

The Incredible Magic of Onions

Onions originated in Western Europe, and have been a staple of European and American cooking since time immemorial. When I was getting my bachelor’s degree, I read medieval poetry written about onions. They’re that old and that awesome.

When someone tells me they don’t like onions, I, quite frankly, don’t believe them. I don’t judge them or belittle them, but I hope and pray for them (and if I cook for them, I often sneak onions into their food anyway and have heard nary a complaint).

Why? Because onions are incredibly versatile. When someone says they “don’t like onions,” usually what they mean is they don’t like raw onion, and they’ve come to associate that raw pungency with anything onion related. What a mistake!

Onions are loaded with vitamins and minerals, as well as antioxidants including flavonoids. Your brain is genetically wired to want and love them, especially when they’re cooked because this makes their healthful properties more accessible for you to digest. Let’s jump into what happens through their stages of cooking.

Stages of Flavor

• Pungent: The first stage of an onion is when it’s raw. At this stage, it is crunchy and incredibly pungent. This is not to be confused with spicy, which onions are not. Rather, they are loaded with sulfur compounds that burn your eyes and make your mouth tingle, but it’s not the same thing as your nerves triggering that “ouch too hot” response that you get from chili peppers.
• Sweet: As you cook an onion, it gradually gets softer, its sulfuric compounds get neutralized, and the natural sugars in the onion begin to sweeten and caramelize. As a result, cooked onions are addictively (yet subtly) sweet, gorgeous to look at, and incredibly aromatic.
• Bitter: If you burn or char an onion, it gets bitter, just like any other food. The difference is in some of our meals we actually like this char. For example, liver and onions, burgers, pizza, grilled chicken—they all benefit from an onion that’s just a tiny bit charred.
• Pickled: Pickling is arguably just another form of cooking, and boy do onions love to get pickled. This adds a lot of acidity and comments on the unique aroma and sugar content of an onion. Pickled red onions are a regular feature in my home, and there’s always a couple of guests at every party who devour them.

Aroma: I don’t include this in the onion’s stages of flavor, but it’s still worth mentioning. Onions pack an incredible amount of aroma, and a good aroma is foundational to the essence of any dish! It’s not for nothing that Italian, French, Creole, Cajun, Spanish, English, and many other foods use onions as part of an aromatic base to the rest of their meal.

Tips for Cooking with Onions

Here are some good tips for helping you get the most out of your onions, no matter how you’re trying to use them:

Raw Onions

Select the Right Onion: Choose sweet or mild varieties like Vidalia or red onions for raw applications to minimize the harshness of flavor.

Soak in Cold Water: Soaking sliced onions in cold water for about 10-15 minutes can help reduce their sharpness and make them milder.

Acid: Toss raw onions with a splash of vinegar or citrus juice and let them marinate for a few minutes to mellow their flavor and add brightness.

My favorite raw onions come in a few ways: sliced thin and soaked in water briefly before going on my burger, sliced ultra thin and tossing in lime juice before going on my tacos, and more.

Caramelized Onions

Low and Slow: Patience is key when caramelizing onions. Cook them over low heat for a long time to allow the natural sugars to develop and the onions to caramelize evenly. When done properly, caramelized onions take 45 minutes to an hour! If you rush it, you’ll burn the edges and make them bitter, or you’ll be forced to add table sugar and cheat yourself of the incredibly indulgent experience.

Use Butter or Oil: Cooking fat prevents the onions from burning and helps release the flavor. My absolute favorite here is butter (we can thank the French for that).

Deglaze the Pan: After caramelizing the onions, deglaze the pan with a splash of wine, broth, or water to scrape up any browned bits and incorporate extra flavor into the onions.

Sweated Onions

Uniform Slicing: For even cooking, slice onions into uniform pieces to ensure they cook at the same rate.

Sauté in Layers: Onions are hardy. If cooking onions with other vegetables, start by sweating the onions first until translucent before adding other ingredients to prevent uneven cooking.

Season with Salt: Add a pinch of salt to the onions as they sweat to draw out moisture and help them cook more evenly. That’s right, you don’t just salt everything at the end, you salt each component in stages to get the best results.

Charred Onions

Preheat the Grill or Pan: Make sure your grill or pan is hot before adding the onions to achieve a nice char without overcooking them.

Brush with Oil: Lightly brush the onions with oil before grilling or charring to prevent sticking and promote even browning.

Watch Closely: Charred onions can quickly go from golden brown to burnt, so keep a close eye on them and flip them frequently for even cooking.

Pickled Onions

Thinly Slice: Thinly slice the onions for quick pickling to ensure they absorb the pickling liquid evenly and pickle faster.

Use Vinegar: Opt for a mild vinegar like white or apple cider vinegar for pickling onions to avoid overpowering their natural flavor.

Add Flavorings: Customize your pickled onions by adding flavorings like garlic, spices, or herbs to the pickling liquid for extra complexity.

My favorite pickled onions are a simple mixture of red onions with white vinegar. If you want to get fancy, add them to a 2:1 ratio of vinegar and water with a handful of white sugar mixed in. But frankly, I just prefer high-quality vinegar and some fresh onions.

All right you onion-breath kitchen geeks. Go forth and cook with onions!