French Onion Soup

Featured in: Everyday Bowl Meals

This beloved bistro classic starts with six large yellow onions slowly cooked until they reach a deep golden-brown caramelization. The process takes patience—about 45 minutes of occasional stirring—but transforms sharp onions into something sweet, savory, and deeply flavorful. Once caramelized, garlic joins the pot followed by white wine to deglaze and capture all those browned bits from the bottom.

Rich beef broth simmers with thyme and bay leaf, infusing the liquid with layers of savory depth. The final touch transforms this into the iconic version we know: thick slices of crusty French bread float atop each bowl, crowned with generous handfuls of grated Gruyère that bubble and brown under the broiler. The contrast between the steaming, aromatic broth and the crisp, cheesy crust creates that perfect spoonful of comfort.

Updated on Wed, 28 Jan 2026 12:19:00 GMT
A classic French Onion Soup with deeply caramelized onions and melted Gruyère cheese in a rich beef broth, served in an oven-safe bowl.  Pin It
A classic French Onion Soup with deeply caramelized onions and melted Gruyère cheese in a rich beef broth, served in an oven-safe bowl. | bowlbuffer.com

The first time I made French onion soup, I cried. Not from emotion, but from those darn onions! Standing there with tears streaming down my face, I kept reminding myself of that perfect bowl I'd had at a tiny Parisian bistro years ago - the sweet caramelized onions, rich broth, and that glorious cheese pull that seemed to stretch for days. The scent that filled my kitchen that afternoon was transformative, turning my apartment into a little corner of France as rain tapped against the windows.

My neighbor Mark knocked on my door the first evening I made this soup, drawn by the aroma that had apparently seeped into the hallway. I invited him to stay, and we sat quietly at my little kitchen table, the only sounds being the clink of our spoons against the bowls and occasional murmurs of appreciation. Now he texts me whenever he smells onions cooking, hoping for another invitation.

Ingredients

  • Yellow onions: The backbone of this recipe, I learned that yellow onions develop the most beautiful caramel flavor when cooked slowly, far better than white or red varieties for this particular dish.
  • Butter and olive oil: Using both prevents the butter from burning while giving you that irreplaceable buttery richness that makes the soup feel indulgent.
  • Beef broth: The foundation of your soup, I once tried making this with store-brand broth and regretted it immediately, so spring for the good stuff or make your own if you have time.
  • Gruyère cheese: Its nutty flavor intensifies as it melts, creating that iconic cheese crown that makes this soup instantly recognizable.

Instructions

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Begin with patience:
Melt the butter with olive oil in your heaviest pot over medium heat, then add those thinly sliced onions. This is when you commit to staying nearby, occasionally stirring as they soften for about 15 minutes.
The transformation:
Sprinkle the softened onions with sugar and salt, then continue cooking and stirring frequently until they reach that magical deep golden color, about 30-40 minutes. You'll notice them shrinking dramatically and developing a sweet, complex aroma.
Building flavor:
Add the minced garlic and cook just until fragrant, about a minute. Then pour in the wine if using, scraping up all those flavorful browned bits from the bottom of your pot.
The simmer:
Add your broth, thyme, bay leaf, and pepper, bringing it to a gentle boil before reducing to a simmer for 30 minutes. Your kitchen will fill with an aroma that makes waiting difficult.
The crowning glory:
Toast those bread slices under the broiler, ladle your soup into oven-safe bowls, and top each with bread and a generous handful of Gruyère. The few minutes under the broiler until the cheese bubbles and browns will feel like an eternity as you anticipate that first spoonful.
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Season soups, salads, meats, and vegetables evenly while cooking with quick, one-handed grinding.
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French Onion Soup bubbling under a broiler, featuring toasted crusty bread topped with golden, bubbly Gruyère cheese.  Pin It
French Onion Soup bubbling under a broiler, featuring toasted crusty bread topped with golden, bubbly Gruyère cheese. | bowlbuffer.com

Last winter during a power outage, I served this soup by candlelight when my in-laws were stranded at our house during a snowstorm. As we sat in the flickering light, my father-in-law, who rarely gives compliments, took a bite and simply said, This tastes like memory. It was perhaps the highest praise Id ever received for my cooking, this recognition that food can transcend ingredients to become something that touches the soul.

The Art of Caramelization

I once tried to rush the onion caramelization process by cranking up the heat, and ended up with a pot of bitter, burned onions that went straight to the trash. The transformation of sharp, pungent raw onions into sweet, melting strands of golden goodness requires gentle heat and time, not unlike how some of the best relationships develop. When youre tempted to increase the heat, remember that youre not just cooking onions, youre conducting an alchemical transformation that forms the entire foundation of your soup.

Choosing Your Cheese

During a particularly tight budget month, I substituted regular Swiss cheese for the Gruyère this recipe calls for and learned an important lesson about balance. While the soup was still good, it missed that distinct nutty depth that Gruyère provides. The cheese isnt just a topping but a crucial flavor component that harmonizes with the sweet onions and savory broth. If Gruyère stretches your budget, a combination of Swiss and a small amount of Parmesan can create a similar complexity at a lower cost.

Serving Suggestions

I discovered the true versatility of French onion soup when I began serving it in different settings, from casual weeknight dinners to more formal gatherings. While traditionally served as a starter, Ive found it substantial enough to be a main course when paired with a crisp green salad dressed simply with lemon and olive oil.

  • For a casual gathering, set out a toppings bar with different cheeses and herbs so guests can customize their bowl.
  • When serving as a main course, consider slightly smaller portions of soup paired with a half sandwich for a balanced meal.
  • Keep extra toasted bread on the side for sopping up those last precious spoonfuls of broth that your spoon cant reach.
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Hearty French Onion Soup garnished with thyme and freshly ground black pepper, served in a rustic ceramic bowl. Pin It
Hearty French Onion Soup garnished with thyme and freshly ground black pepper, served in a rustic ceramic bowl. | bowlbuffer.com

This soup connects us to centuries of French culinary tradition, to countless home cooks who stood stirring onions just as we do today. As you lift that first spoonful, breaking through the blanket of melted cheese, youre not just eating soup, youre participating in a delicious piece of history.

Recipe FAQ

How long does it take to properly caramelize onions?

Plan on about 45 minutes total. First, cook the onions for 15 minutes until softened. After adding sugar and salt, continue cooking for another 30–40 minutes, stirring frequently, until they reach a deep golden brown color. This slow cooking process is essential for developing that signature sweetness and depth of flavor.

Can I make this vegetarian?

Absolutely. Simply substitute the beef broth with a high-quality vegetable broth. The rest of the preparation remains the same. For additional depth in the vegetarian version, you might consider adding a splash of balsamic vinegar or a bit of soy sauce to mimic the umami notes that beef broth typically provides.

What type of onions work best?

Yellow onions are ideal for this dish because they strike the perfect balance between sweetness and pungency. As they caramelize, their natural sugars develop beautifully. You could also use a mix of yellow and red onions for slightly different flavor notes, though avoid sweet onions as they may become overly sugary during the long cooking process.

What cheese alternatives can I use?

Gruyère is traditional thanks to its excellent melting properties and nutty flavor. Emmental or Swiss cheese make great substitutes with similar characteristics. For something different, try Comté or a blend of Gruyère with a bit of Parmesan for extra savory depth. Just ensure whatever cheese you choose melts well and has enough flavor to stand up to the rich broth.

Can this be made ahead of time?

Yes, actually the flavors improve when made ahead. Prepare the soup completely through step 5, then refrigerate for up to 3 days. When ready to serve, reheat gently and proceed with the bread and cheese topping. For the best results, add the toasted bread and cheese just before serving—this keeps the bread crisp and prevents it from becoming soggy.

Why add sugar to the onions?

The small amount of sugar helps the onions caramelize more evenly and efficiently. Onions naturally contain sugars, but adding a teaspoon encourages the browning process and ensures consistent results. It doesn't make the final dish noticeably sweet—that sweetness is balanced by the savory broth, wine, and salty cheese.

French Onion Soup

Rich broth with caramelized onions, crusty bread, and melted Gruyère cheese topping.

Prep Time
20 min
Cook Time
75 min
Overall Time
95 min
Created by Anthony Perry


Skill Level Medium

Cuisine Type French

Makes 4 Portions

Dietary Information None specified

What You'll Need

Onions

01 6 large yellow onions, thinly sliced
02 2 tablespoons unsalted butter
03 1 tablespoon olive oil

Broth

01 6 cups beef broth or vegetable broth for vegetarian option
02 1/2 cup dry white wine, optional

Flavorings

01 2 cloves garlic, minced
02 1 teaspoon sugar
03 1 teaspoon salt
04 1/2 teaspoon freshly ground black pepper
05 2 sprigs fresh thyme or 1/2 teaspoon dried thyme
06 1 bay leaf

Topping

01 4 slices crusty French bread, about 1 inch thick
02 2 cups grated Gruyère cheese

Directions

Step 01

Sauté onions: In a large heavy-bottomed pot, melt butter with olive oil over medium heat. Add sliced onions and cook, stirring occasionally, until softened, about 15 minutes.

Step 02

Caramelize onions: Sprinkle onions with sugar and salt. Continue cooking, stirring frequently, until onions are deeply golden and caramelized, 30 to 40 minutes.

Step 03

Add garlic: Add minced garlic and cook for 1 minute more.

Step 04

Deglaze pot: Pour in white wine if using and scrape up browned bits from the bottom of the pot. Simmer for 2 to 3 minutes.

Step 05

Simmer broth: Add beef broth, thyme, bay leaf, and black pepper. Bring to a boil, then reduce heat and simmer uncovered for 30 minutes. Remove and discard thyme sprigs and bay leaf.

Step 06

Toast bread: Preheat broiler. Arrange bread slices on a baking sheet and toast under broiler until lightly golden on both sides.

Step 07

Assemble bowls: Ladle hot soup into oven-safe bowls. Top each with a slice of toasted bread and generous handful of Gruyère cheese.

Step 08

Broil and serve: Place bowls under broiler until cheese is melted and bubbling, 2 to 3 minutes. Serve immediately.

Equipment Needed

  • Large heavy-bottomed pot
  • Wooden spoon
  • Knife and cutting board
  • Cheese grater
  • Oven-safe soup bowls
  • Baking sheet

Allergy Info

Inspect every ingredient for potential allergens and see a health expert if uncertain.
  • Contains milk from butter and cheese
  • Contains gluten from bread
  • Use gluten-free bread for gluten-free preparation
  • Use vegan butter and cheese alternatives for dairy-free preparation

Nutrition Details (for each serve)

These nutrition details are for reference and not intended as a substitute for professional advice.
  • Kcal: 435
  • Fats: 21 g
  • Carbohydrates: 41 g
  • Proteins: 20 g