Best French Onion Soup We’ve Made

This classic French onion soup is rich, savory, and deeply comforting, made with perfectly caramelized onions, aromatic broth, and golden, garlic-rubbed baguette slices topped with bubbling Gruyère cheese. With a handful of ingredients and some patience, you can recreate this elegant, restaurant-worthy dish at home.

Why You’ll Love This Recipe

• Deep, rich flavor from slow-cooked caramelized onions

• Elegant enough for entertaining, yet cozy and satisfying

• Oven-broiled cheesy bread topping adds irresistible texture

• Customizable with different broths and cheeses

• Can be made alcohol-free with simple substitutions

• A perfect balance of savory, sweet, and umami

• Ideal for colder months or special occasions

• Impressive presentation in individual oven-safe bowls

• Makes a hearty main dish or flavorful starter

• Better than most versions you’ll find in restaurants

Ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

• Yellow onions

• Salted butter

• Sweet vermouth or alternatives like sherry or brandy

• Dry white wine or Lillet Blanc

• Chicken broth or beef stock

• Fresh thyme leaves

• Fine sea salt

• French baguette or rustic loaf

• Garlic cloves

• Gruyère cheese

Directions

1. Melt the butter in a wide, heavy-bottomed pot over medium heat.

2. Stir in the sliced onions and cover with a lid. Cook for 12 to 15 minutes until translucent.

3. Remove the lid and cook uncovered, stirring frequently, for 45 to 60 minutes until the onions are deep golden and caramelized.

4. Add vermouth and white wine, scraping up browned bits. Cook for about 2 minutes until alcohol aroma fades.

5. Stir in broth, thyme, and salt. Cover and simmer for 5 minutes. Adjust salt to taste. Turn off the heat and let the soup steep.

6. Preheat oven to 400°F (204°C). Butter the bread slices and toast them for 5–6 minutes.

7. Rub toasted bread with garlic cloves. Briefly dunk into the soup to absorb flavor.

8. Place one slice of bread in the bottom of each oven-safe soup bowl. Sprinkle with cheese. Add soup, then top with two more bread slices and more cheese.

9. Place bowls on a baking sheet and broil until the cheese is melted and bubbly. Serve hot.

Servings and timing

Servings: 4
Prep time: 15 minutes
Cook time: 1 hour 15 minutes
Total time: 1 hour 30 minutes

Variations

• Alcohol-free version: Skip wine and vermouth; deglaze with broth and add a splash of sherry vinegar for brightness.

• Vegetarian option: Use vegetable broth instead of chicken or beef stock.

• Cheese swaps: Try Swiss, fontina, mozzarella, or parmesan if Gruyère is unavailable.

• Different breads: Rustic sourdough or ciabatta work well in place of baguette.

• Herb twist: Add a bay leaf or a sprig of rosemary while simmering for deeper aroma.

• Spicy edge: Add a pinch of crushed red pepper flakes to the onions for a subtle heat.

• Broth blend: Mix chicken and beef broth for a balanced, nuanced flavor.

• Red wine version: Substitute white wine with a dry red for a richer, bolder taste.

• Vegan-friendly: Use vegan butter, vegetable broth, and dairy-free cheese.

• Crockpot caramelizing: Start onions in a slow cooker before transferring to stovetop to finish the soup.

Storage/Reheating

Storage:
Let the soup cool completely, then transfer to airtight containers. Store in the refrigerator for up to 4 days.

Freezing:
French onion soup (without the bread and cheese topping) freezes well. Freeze in airtight containers for up to 3 months. Thaw overnight in the fridge before reheating.

Reheating:
Warm the soup on the stove over medium heat until hot. Toast fresh bread, rub with garlic, top with cheese, and broil as directed for serving.

FAQs

How do I caramelize onions without burning them?

Cook slowly over medium heat, stirring often. If they begin to stick, deglaze the pan with a splash of water, broth, or wine.

Can I make French onion soup without alcohol?

Yes. Omit wine and vermouth. Deglaze with broth and add a splash of sherry vinegar or a dash of fish sauce for depth.

What is the best onion for French onion soup?

Yellow onions are ideal for balanced sweetness and depth. Avoid using only sweet onions unless you prefer a sweeter soup.

Can I make this soup in advance?

Absolutely. It actually tastes better the next day as the flavors develop. Store the soup base and assemble with fresh bread and cheese before serving.

What’s the best cheese for French onion soup?

Gruyère is the top choice for its meltability and nutty flavor. Alternatives include Swiss, fontina, parmesan, or mozzarella.

Can I use store-bought broth?

Yes, but opt for low-sodium chicken broth. Store-bought beef broth can be too salty and lacks depth.

What kind of wine should I use?

A dry white wine like Sauvignon Blanc or Lillet Blanc works best. Avoid overly sweet wines unless balancing with acidity.

Is it necessary to broil the cheese topping?

Broiling melts the cheese to golden, bubbly perfection. It’s a key step for achieving the classic look and flavor of French onion soup.

Can I freeze the assembled soup?

It’s best to freeze the soup base only. Add fresh bread and cheese when reheating for the best texture and taste.

Why dunk the bread before adding it to the bowl?

Pre-soaking the bread prevents it from absorbing too much broth in the bowl, ensuring better balance in each spoonful.

Conclusion

This French onion soup is a true classic that delivers rich, satisfying flavor with every bite. The caramelized onions, garlic-rubbed toast, and bubbling cheese create a warm, comforting dish that’s perfect for cozy nights or elegant dinners. With its simple ingredients and foolproof method, it’s a recipe you’ll turn to again and again.