French Onion Soup

Rich, deeply flavorful, and downright decadent, French onion soup is the treat-yourself comfort food I’ll never tire of. So much so that I’ve found infinite ways to sneak in the iconically savory caramelized onion and cheese flavor combo into pretty much everything (see: French onion soup bites, one-pot French onion pasta, and French onion gnocchi soup). But what really makes the original French onion soup so special is how it’s both perfect for curling up with during cold winter nights, while also being an incredible dish to impress party guests. If you’re an avid fan, you might notice that my recipe strays a bit from the classic, but I promise this version remains one of the richest, most comforting soups on the block.

What People Are Saying:
“The absolute best recipe!! Takes a while to brown the onions but it's so worth it.” - hlynr

“I made this for tonight! I already had a bowl with the bread and it was DELICIOUS.” - OlivePopsicle

How To Make French Onion Soup

INGREDIENTS

• Yellow Onions: The classic French method calls for yellow onions, but what's truly important is how you slice them. It's important that the onions cook and caramelize evenly, so you'll need even slices. To achieve this, remove the top and bottom of the onion, halve from root to stem, peel, and cut each half into vertical 1/4"-thick slices. Slicing too thin will lead to mushy, overcooked, or burnt onions.
• Unsalted Butter: When in doubt, always go unsalted with your butter. It allows you to control the salt levels and season as you go, while also caramelizing the onions beautifully.
• All-Purpose Flour: French onion soup is hearty and much of that is thanks to a bit of all-purpose flour. Adding it prior to all your many broths allows the soup to thicken up and concentrate the richness.
• Thyme: Woodsy, subtly floral thyme adds a bite of peppery flavor that helps cut some of the richness of this to this savory soup.
• Low-Sodium Beef & Chicken Stock: We prefer to use a combo of chicken stock and beef stock (over just beef stock) in our soup. The soup will still taste just as rich, but slightly lightened up, with a low-sodium broth giving you more control over those salt levels.
• Dry White Wine: White wine brings a sweetness that intensifies the sweet onions, but there are other wines you can use to achieve a similar effect. Brandy, dry vermouth, sweet red wine, or Marsala also make for a richly flavored soup.
• Gruyère: Gruyère is the classic choice for French onion soup (and my personal favorite), but you can use another melty cheese if you prefer. If you want to use a different cheese (or add another), Parmesan, Swiss, and fontina would all be welcome additions.
• Baguette Slices: Since you're already spending plenty of time cooking down onions, feel free to opt for slices of your favorite store-bought baguette—the crustier, the better. That being said, I love an overachiever, so don't be afraid to go all out and make your own baguette.

STEP-BY-STEP INSTRUCTIONS

Alright, it’s time to practice a virtue, and that virtue is the patience you need to cook down all those yellow onions. In a large pot over medium heat, melt your butter, and add the onions and cook, stirring occasionally, until deeply golden brown, which will take between 45 and 60 minutes. It might be tempting to ramp up the heat, but resist the urge! There will be no burnt onions on our watch.

Next, it’s time to add the flour to your onions and continue to cook. Stir the mixture until fully incorporated for another 1 to 2 minutes. Then season with salt and add the dry white wine, bringing it all to a simmer and stirring occasionally, until evaporated, for another 1 to 2 minutes.

Now, all your onion-y patience will really start to pay off. Add the beef stock, chicken stock, and thyme to the pot and bring to a boil. Then reduce the heat to medium-low and bring to a simmer. Continue to cook, stirring occasionally, until liquid is slightly reduced and flavors have melded, which will take about 15 minutes more. Remove your thyme sprigs, and season the soup with salt and pepper.

With all this rich, savory soup on your hands, you’ll obviously need some bread and cheese to go with it, preferably right on top. Heat your broiler to high, and ladle the soup into heatproof ramekins and place on a rimmed baking sheet. Top each ramekin with 2 baguette slices, then top with cheese.

Once topped, broil the soup in the oven, watching closely, until bubbling and golden, for about 1 to 2 minutes.

Full list of ingredients and directions can be found in the recipe below.

Recipe Tips

• Avoid bitter soup: Burnt onions are the main culprit when it comes to bitterness. Keep an eye on the onions as they cook and reduce the heat if necessary to keep them from burning instead of caramelizing.
• Watch the cheese: When it comes to cheese, you want to avoid adding so much that your bread sinks under the weight. A full ramekin is the key to cheesy bread that stays on top of your soup. If the bread starts to sink, try adding more onions to keep the bread afloat.
• What do you serve with French onion soup? Salads and sandwiches always make great soup sidekicks. You can stick with the classics like chicken Caesar salad or a club sandwich, or get creative with a garlic-herb wedge salad or a fully loaded veggie sandwich.

Storage

You can store leftover soup (without bread and cheese) in an airtight container for up to 5 days, or freeze for up to 3 months.