Ingredients
For the Soup
- 4 tablespoons unsalted butter
- 2 tablespoons olive oil
- 4 large yellow onions, thinly sliced
- 2 large sweet onions, thinly sliced
- 1 teaspoon salt
- ½ teaspoon black pepper
- 1 teaspoon granulated sugar
- 4 cloves garlic, minced
- ½ cup dry white wine (optional)
- 8 cups beef broth
- 2 teaspoons Worcestershire sauce
- 2 bay leaves
- 2 sprigs fresh thyme (or 1 teaspoon dried thyme)
For the Topping
- 1 French baguette, sliced into ½-inch rounds
- 2 tablespoons olive oil
- 2 cups shredded Gruyère cheese
- 1 cup shredded mozzarella cheese
- ½ cup grated Parmesan cheese
Optional Garnish
- Fresh thyme leaves
- Chopped parsley
Instructions
Step 1: Caramelize the Onions
In a large Dutch oven or heavy-bottomed pot, melt the butter with the olive oil over medium heat.
Add the sliced onions, salt, pepper, and sugar.
Cook slowly for 40–50 minutes, stirring frequently, until the onions become deep golden brown and caramelized.
Do not rush this step—the rich flavor of French Onion Soup comes from properly caramelized onions.
Step 2: Add Garlic and Deglaze
Stir in the minced garlic and cook for 1 minute until fragrant.
Pour in the white wine and scrape up any browned bits from the bottom of the pot.
Cook for 2–3 minutes until the wine has reduced slightly.
Step 3: Simmer the Soup
Add:
- Beef broth
- Worcestershire sauce
- Bay leaves
- Thyme
Bring the soup to a gentle boil.
Reduce heat and simmer uncovered for 25–30 minutes.
Taste and adjust seasoning with additional salt and pepper if needed.
Remove the bay leaves before serving.
Step 4: Prepare the Bread
While the soup simmers, preheat the oven to 400°F (200°C).
Arrange the baguette slices on a baking sheet.
Brush lightly with olive oil.
Bake for 8–10 minutes, turning once, until golden and crisp.
Set aside.
Step 5: Assemble the Soup
Preheat the broiler.
Ladle the hot soup into oven-safe bowls.
Place 2–3 toasted baguette slices on top of each bowl.
Generously cover with:
- Gruyère cheese
- Mozzarella cheese
- Parmesan cheese
Step 6: Broil
Place the bowls on a baking sheet.
Broil for 2–4 minutes, or until the cheese is melted, bubbly, and golden brown.
Watch carefully to prevent burning.
Step 7: Serve
Carefully remove the bowls from the oven.
Garnish with fresh thyme or parsley if desired.
Serve immediately while the cheese is hot and stretchy.
Why You’ll Love This Recipe
- Rich, deeply caramelized onion flavor
- Restaurant-quality comfort food
- Perfect for cold weather
- Beautiful cheesy topping
- Great for entertaining
- Made with simple ingredients
Delicious Variations
Vegetarian French Onion Soup
Replace beef broth with rich vegetable broth.
Red Wine Version
Use dry red wine instead of white wine for deeper flavor.
Mushroom French Onion Soup
Add sliced mushrooms while caramelizing the onions.
Slow Cooker Version
Transfer caramelized onions and broth to a slow cooker and cook on low for 4–6 hours.
Extra Cheesy Soup
Double the Gruyère for an even richer topping.
Expert Tips
Be Patient with the Onions
True caramelization takes time. Slow cooking develops the soup’s signature sweet and savory flavor.
Use Gruyère Cheese
Gruyère melts beautifully and provides authentic French Onion Soup flavor.
Toast the Bread Well
Crispy bread helps prevent sogginess after it’s added to the soup.
Use Quality Broth
A rich broth creates a more flavorful soup.
Serve Immediately
French Onion Soup is best enjoyed fresh from the broiler while the cheese is bubbly.
Storage
Refrigerator
Store the soup (without bread and cheese) in an airtight container for up to 4 days.
Freezer
Freeze the soup base for up to 3 months.
Reheating
Reheat the soup on the stovetop and add fresh bread and cheese before broiling.
Serving Suggestions
Pair French Onion Soup with:
- Caesar salad
- Mixed green salad
- Roast chicken
- Steak
- Crusty artisan bread
- Roasted vegetables
- Charcuterie boards
Nutritional Information (Approximate Per Serving)
- Calories: 420
- Protein: 18g
- Carbohydrates: 30g
- Fat: 24g
- Fiber: 3g
- Sugar: 8g
Rich, savory, and crowned with bubbling golden cheese, this Classic French Onion Soup is the ultimate comfort dish. Every spoonful is packed with sweet caramelized onions, flavorful broth, and melted cheese for a truly unforgettable dining experience.
