Classic French Onion Soup

Featured in: Sip Crunch

This beloved bistro classic features thinly sliced yellow onions slowly cooked until deeply golden and sweet, creating a rich, flavorful foundation. Simmered in aromatic beef broth with herbs and a splash of white wine, the soup develops incredible depth. Each serving is finished with toasted crusty bread and generous amounts of nutty Gruyère cheese, melted until bubbling and golden. The result is a warming, satisfying dish perfect for cold weather or whenever you crave ultimate comfort food. Pair with a glass of wine for the complete French bistro experience.

Updated on Tue, 27 Jan 2026 15:13:00 GMT
French Onion Soup served in a rustic bowl with melted Gruyère bubbling over crusty bread. Save
French Onion Soup served in a rustic bowl with melted Gruyère bubbling over crusty bread. | kookycrunch.com

There's something almost meditative about standing at the stove on a gray afternoon, watching onions transform from sharp and crisp to golden pools of sweetness. My first real French onion soup came together almost by accident—I had a pot of onions going while waiting for friends to arrive, and instead of rushing through, I let them have the time they needed. That patience changed everything, and now whenever I make this soup, I'm transported back to that kitchen, where the smell alone felt like an invitation.

I made this for my neighbor last winter after he mentioned feeling under the weather, and watching his face when he tasted it—especially that first spoonful of melted cheese and bread—reminded me why cooking for others matters. He said it tasted like a hug, and I've been making it ever since whenever someone needs comfort on a cold night.

Ingredients

  • Large yellow onions: Six of them might seem like overkill until you watch them shrink down to pure golden flavor—they're the backbone here, so don't skimp or use red onions which taste different.
  • Unsalted butter and olive oil: The combination of both gives you richness without burning; use the butter for flavor and the oil to raise the smoke point.
  • Beef broth: Quality matters more than you'd think, so taste it first and adjust seasoning at the end.
  • Dry white wine: Optional but genuinely elevates the soup with a subtle depth that broth alone can't reach.
  • Garlic, sugar, and salt: The sugar isn't about making it sweet—it amplifies the onion caramelization and balances everything.
  • Fresh thyme and bay leaf: These herbs whisper in the background; dried thyme works if fresh isn't available, but use half the amount.
  • Crusty French bread: Thick slices are essential so they don't disintegrate into the soup; day-old bread is actually better than fresh.
  • Gruyère cheese: The nuttiness is irreplaceable here, though Emmental works in a pinch.

Instructions

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Start the foundation:
Melt butter with olive oil in your pot over medium heat, then add all those sliced onions at once. Stir occasionally for about fifteen minutes until they soften and release their moisture—you'll hear them sizzle and smell something sweet starting to develop.
Build the caramel:
Here's where patience becomes your secret weapon: sprinkle sugar and salt over the onions, then stir frequently as they turn from pale to golden to deep amber, about thirty to forty minutes. Lower the heat if they're browning too fast, and scrape up any stuck bits from the bottom—that's pure flavor.
Deepen the flavor:
Add minced garlic and let it cook for just one minute until fragrant but not burned. This moment matters because overcooked garlic turns bitter.
Deglaze with wine:
Pour in white wine if using, scraping up all those browned caramelized bits stuck to the pot—this is called deglazing and those bits are liquid gold. Let it simmer for two to three minutes while the alcohol cooks off.
Simmer the soup:
Add beef broth, thyme sprigs, bay leaf, and pepper, then bring to a boil before reducing to a gentle simmer for thirty minutes uncovered. This lets flavors marry and deepens, and you can taste it toward the end to adjust seasoning.
Toast the bread:
While the soup finishes, preheat your broiler and toast bread slices on a baking sheet until both sides turn lightly golden. This keeps them from getting soggy too quickly when they hit the hot soup.
Assemble the magic:
Ladle hot soup into oven-safe bowls, top each with a slice of toasted bread, then pile on a generous handful of grated Gruyère. Place under the broiler for two to three minutes until cheese bubbles and browns slightly at the edges.
Serve with care:
These bowls come out of the broiler piping hot, so warn anyone eating that the handles and rims will burn fingers—learned that one the hard way.
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Ideal for slow-simmered sauces, braised vegetables, baked dips, and cozy one-pot meals with even heat.
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Fresh thyme garnish sits atop the cheesy crust of this classic French bistro dish. Save
Fresh thyme garnish sits atop the cheesy crust of this classic French bistro dish. | kookycrunch.com

There's a moment when everyone at the table goes quiet after that first spoonful—cheese stretching, bread giving way, warm broth coating everything—and you know you've made something memorable. That's the real payoff of this soup, more than any compliment could tell you.

The Caramelization Secret

The difference between regular soup and restaurant-quality French onion soup lives entirely in those golden onions. Most home cooks skim this step or rush it, but I learned that every extra minute of low-heat stirring adds complexity and sweetness that can't be faked.

Cheese and Bread Chemistry

The toasted bread does two things: it creates a barrier so the cheese doesn't sink into the soup immediately, and it adds a subtle crunch that contrasts beautifully with everything soft. Some people use day-old bread specifically because fresh bread gets too soggy, and honestly that's worth remembering next time you have crusty bread hanging around.

Variations and Timing

This soup actually tastes even better the next day after flavors have settled, so making it ahead takes pressure off when guests arrive. You can refrigerate it for up to three days, then reheat gently before finishing with the bread and cheese toast under the broiler.

  • For vegetarian versions, swap vegetable broth for beef and the soup loses nothing—the onions carry all the depth.
  • A garlic-rubbed toasted bread slice before the cheese adds another layer if you're feeling adventurous.
  • Pair with a dry white wine or light red to echo the wine already in the pot.
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Deeply caramelized onions float in rich beef broth beneath golden, toasted bread slices. Save
Deeply caramelized onions float in rich beef broth beneath golden, toasted bread slices. | kookycrunch.com

This soup has become my go-to when someone needs real comfort or when I want to prove that simple ingredients deserve respect. Every bowl that comes out of the oven reminds me that good food often starts with patience and ends with someone feeling genuinely cared for.

Recipe FAQ

How do you achieve perfectly caramelized onions?

Cook sliced onions slowly over medium heat with butter and olive oil for about 45 minutes total. First soften them for 15 minutes, then add sugar and salt to encourage browning. Stir frequently during the final 30 minutes until they reach a deep golden color and develop rich, sweet flavor.

What type of onions work best?

Yellow onions are ideal for French onion soup as they become naturally sweet when cooked down. You can also use a mix of yellow and red onions for slightly different flavor notes. Avoid sweet onions as they don't caramelize as well.

Can I make this vegetarian?

Absolutely. Simply substitute vegetable broth for the beef broth. The depth of flavor comes primarily from the caramelized onions, so the soup remains incredibly satisfying even without beef broth. You can also add a splash of balsamic vinegar for extra richness.

What cheese alternatives can I use?

Gruyère is traditional for its nutty flavor and excellent melting properties. Good alternatives include Emmental, Swiss cheese, Comté, or a blend of provolone and Parmesan. For a dairy-free version, use vegan cheese alternatives that melt well.

How do I store and reheat leftovers?

Store the soup and topping components separately. Keep the soup refrigerated for up to 4 days or freeze for 3 months. When ready to serve, reheat the soup on the stovetop, toast fresh bread, and add cheese just before broiling. This prevents the bread from becoming soggy.

What wine pairs well with this dish?

A dry white wine used in the cooking, such as Sauvignon Blanc or Pinot Grigio, makes an excellent pairing. If you prefer red, opt for a light-bodied choice like Pinot Noir or Beaujolais that won't overpower the delicate onion flavor.

Classic French Onion Soup

Comforting bowl of deeply caramelized onions in rich broth with melted Gruyère and crusty bread

Prep duration
20 min
Cook duration
75 min
Complete duration
95 min
Created by Jake Peterson

Type Sip Crunch

Skill level Medium

Heritage French

Output 4 Portions

Diet considerations None specified

Components

Onions

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

Broth

01 6 cups beef broth
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
06 1 bay leaf

Topping

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

Directions

Phase 01

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

Phase 02

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

Phase 03

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

Phase 04

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

Phase 05

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

Phase 06

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

Phase 07

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

Phase 08

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

Necessary tools

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

Allergy details

Review each component carefully for potential allergens and consult with healthcare professionals if you're uncertain about any ingredient.
  • Contains milk (butter and cheese)
  • Contains gluten (bread)
  • Use gluten-free bread for gluten-free preparation
  • Use vegan butter and cheese alternatives for dairy-free preparation

Nutrient breakdown (per portion)

These values are estimates only and shouldn't replace professional medical guidance.
  • Energy: 435
  • Fats: 21 g
  • Carbohydrates: 41 g
  • Proteins: 20 g