If you have ever dreamed of savoring a soul-warming bowl of french onion soup that hits all the right notes, then this Classic French Onion Soup with Gruyere and Toasted Baguette Recipe is your new best friend in the kitchen. With deeply caramelized onions bathing in a rich, herb-infused beef broth and crowned by a glorious crown of toasted baguette and bubbling Gruyere cheese, every spoonful is a celebration of comfort and flavor. It’s the kind of recipe that brings people together around the table and turns any ordinary day into a cozy occasion.
Ingredients You’ll Need
This recipe uses simple, classic ingredients that come together to create an unbeatable flavor profile and texture. Each element plays a crucial role, from the buttery sweetness of the onions to the savory complexity of the broth and the satisfying crunch and melty cheese topping of the baguette.
- Yellow onions (4 large): Thinly sliced for perfect caramelization and that signature deep, sweet flavor.
- Butter (4 tablespoons): Used to gently cook the onions, adding richness and preventing sticking.
- Kosher salt (1 tablespoon): Enhances flavor and helps draw moisture from onions for perfect caramelization.
- Cayenne pepper (1/4 teaspoon, optional): Adds a subtle warmth that balances the sweetness of the onions.
- All-purpose flour (2 tablespoons): Thickens the soup slightly and helps create a luscious mouthfeel.
- Sherry or white wine (1/2 cup): Deglazes the pan and adds a bright layer of acidity.
- Fresh lemon juice (1 tablespoon): Boosts brightness and balances the savory broth.
- Beef broth (8 cups): The hearty backbone of the soup, preferably high quality for deep flavor.
- Water (2 cups): Helps mellow the broth while keeping it light and clear.
- Better Than Bouillon Beef Base (1 tablespoon): Concentrated flavor that intensifies your homemade broth.
- Carrots, onion, celery (3 carrots, 1 yellow onion, 2 stalks celery): Added to broth for complexity and subtle sweetness.
- Garlic (6 cloves): Smashed to impart a gentle aroma and depth.
- Prepared horseradish (1 teaspoon): Adds a unique spicy edge to the broth.
- Fresh thyme, rosemary, bay leaves, peppercorns: Herbs and spices that infuse the broth with earthy, fragrant notes.
- French bread (1 loaf): Sliced thickly and toasted for that crunchy, golden topping.
- Gruyere cheese (1 cup, grated): The star cheese that melts beautifully for gooey goodness.
- Parmesan cheese (1 cup, grated): Adds a sharp, nutty flavor to complement the Gruyere.
- Swiss cheese (8 ounces, sliced): Extra layer of creamy meltiness on top of the soup bowls.
- Fresh chives and freshly cracked black pepper: Garnish with fresh brightness and spice.
How to Make Classic French Onion Soup with Gruyere and Toasted Baguette Recipe
Step 1: Slice the Onions
Start by thinly slicing about 4 large yellow onions until you have roughly 8 cups. The thinner the slices, the better they caramelize evenly, transforming into a silky, golden base that offers all the rich sweetness we want without any harsh onion bite. This step sets the foundation for the soup’s flavor, so take your time.
Step 2: Caramelize the Onions
Melt 4 tablespoons of butter in a roomy, high-sided pan over medium heat. Add your sliced onions, sprinkle on kosher salt and cayenne pepper if you’re feeling adventurous. Stir occasionally while cooking for about 10 minutes until the onions become translucent, releasing their natural sugars. Then reduce the heat to medium-low and continue caramelizing for 90 minutes, stirring every 10-20 minutes. This slow cooking is where magic happens — the onions develop a deep golden color and sweet complexity, no browning edges allowed!
Step 3: Prepare the Broth
While the onions do their thing, bring your beef broth, water, and Better Than Bouillon beef base to a boil in a large stockpot. Toss in chopped carrots, a yellow onion, celery, smashed garlic cloves, prepared horseradish, thyme, rosemary, bay leaves, and peppercorns. Lower the heat and let this flavorful broth simmer gently while your onions caramelize. The blend of herbs and veggies creates a rich, aromatic broth that will lift the entire dish.
Step 4: Strain the Broth
Once your broth has simmered for around 90 minutes and the onions are perfectly caramelized, strain the broth through a colander, discarding the vegetables and herbs. Return the clear, deeply flavored broth to the pot to keep warm — this step ensures a smooth soup base without any unwanted bits.
Step 5: Add Flour and Deglaze
Sprinkle flour over your caramelized onions and cook for 1 to 2 minutes to eliminate any raw flour taste. Then pour in your wine or sherry to deglaze the pan, scraping up all the golden, flavorful bits stuck to the bottom. Add lemon juice and continue cooking until the liquid mostly evaporates — this creates a luxurious, slightly thickened onion mixture bursting with layers of flavor.
Step 6: Combine Onions and Broth
Transfer the rich onion mixture into the warm strained broth and stir everything together. Taste and adjust seasoning by adding more salt, horseradish, or herbs as your palate desires. This is where the flavors marry perfectly, and the soup reaches its full-bodied glory.
Step 7: Prepare the Bread
Preheat your oven to 350°F and slice your French bread into 1-inch-thick rounds. Lay the slices on a baking sheet and toast them for 10 minutes, flip, then toast for 5 more minutes until each side is beautifully crisp. For an extra touch of decadence, butter your bread slices before toasting. This crunchy, buttery base will give incredible texture under the melty cheese.
Step 8: Assemble and Broil
Grate your Gruyere and Parmesan cheeses. In oven-safe bowls, place a small spoonful of Gruyere and Parmesan on the bottom, ladle in the hot soup, then top each bowl with a toasted bread slice and a generous sprinkling of more Gruyere and Parmesan. Finally, nestle a slice of Swiss cheese on top. Arrange the bowls on a baking sheet and pop them in the oven under the broiler for 2 to 4 minutes or until the cheeses bubble and turn golden brown. Carefully remove, garnished with fresh chives and cracked black pepper, and serve immediately.
How to Serve Classic French Onion Soup with Gruyere and Toasted Baguette Recipe
Garnishes
Freshly chopped chives and a crack of black pepper add not just color but a fresh herbal lift to each steaming bowl. Don’t underestimate the difference that this simple final touch makes — it brightens and elevates each spoonful, making the soup feel even more special.
Side Dishes
This soup is charmingly hearty on its own, but if you’re hosting or want some variety, pair it with a crisp green salad with a light vinaigrette or a platter of roasted vegetables. The fresh, clean flavors beautifully balance the rich and savory depth of the soup without overpowering it.
Creative Ways to Present
For a rustic touch, serve the soup in mini cast-iron pots if you have them, or bread bowls for a fun twist that combines bread and soup all in one. You can also sprinkle finely chopped fresh herbs like thyme or parsley on top for a more fragrant presentation. The Classic French Onion Soup with Gruyere and Toasted Baguette Recipe is versatile and goes from cozy home meal to elegant starter with just a few tweaks.
Make Ahead and Storage
Storing Leftovers
Once cooled, store leftover soup in an airtight container in the refrigerator for up to 3 days. Keep the bread and cheese toppings separate if possible to maintain their texture.
Freezing
This soup freezes well if kept without the bread and cheese. Store in a freezer-safe container for up to 3 months. Thaw overnight in the fridge before reheating gently on the stove.
Reheating
Reheat the soup slowly on the stovetop over low heat, stirring occasionally. Add fresh toasted baguette slices and cheeses just before serving, then broil briefly to achieve that perfect gratin finish again.
FAQs
Can I make this soup vegetarian?
The rich beef broth is essential for the classic flavor, but you can substitute with a high-quality vegetable broth and add mushrooms for an umami boost if you want a vegetarian twist.
What cheese works best besides Gruyere?
Gruyere is traditional for its meltability and nutty flavor, but Swiss cheese, Emmental, or even a good-quality mozzarella can be used if needed.
How do I keep the onions from burning during caramelization?
Patience is key. Cook over medium-low heat and stir often, scraping the pan’s bottom to prevent scorching. If they are sticking or browning too fast, lower the heat further.
Can I use store-bought French bread?
Absolutely! Just pick a crusty baguette with a firm crumb for the best texture after toasting and soup soaking.
Why do we add flour to the onions?
The flour helps thicken the soup slightly and ensures a smooth, velvety texture, preventing it from feeling too watery.
Final Thoughts
Now that you have this incredible Classic French Onion Soup with Gruyere and Toasted Baguette Recipe in your hands, there’s no reason to wait for a chilly day to experience the magic. It’s a recipe that fills your home with inviting aromas and your heart with warmth. Give it a go—your taste buds and guests will thank you endlessly for this timeless, comforting classic!
Print
Classic French Onion Soup with Gruyere and Toasted Baguette Recipe
- Prep Time: 20 minutes
- Cook Time: 1 hour 30 minutes
- Total Time: 1 hour 50 minutes
- Yield: 7 servings
- Category: Soup
- Method: Stovetop
- Cuisine: French
Description
This classic French Onion Soup recipe features deeply caramelized onions simmered in a rich, flavorful beef broth, topped with toasted French bread and a blend of melted Gruyere, Parmesan, and Swiss cheeses. Perfect for a cozy meal, this soup balances sweet, savory, and cheesy elements with an aromatic herb-infused broth.
Ingredients
Onions and Butter
- 4 large yellow onions (about 3 pounds), thinly sliced
- 4 tablespoons butter (half stick)
- 1 tablespoon kosher salt (use less if using table salt)
- 1/4 teaspoon cayenne pepper (optional)
Thickening and Flavor Enhancers
- 2 tablespoons all purpose flour
- 1/2 cup sherry wine or white wine
- 1 tablespoon fresh lemon juice (about half a lemon)
Broth Ingredients
- 8 cups high quality beef broth
- 2 cups water
- 1 tablespoon Better Than Bouillon Beef Base
- 3 carrots, peeled and roughly chopped
- 1 yellow onion, roughly chopped
- 2 stalks celery, roughly chopped
- 6 large cloves garlic, smashed
- 1 teaspoon prepared horseradish (or more, to taste)
- 3 sprigs fresh thyme (or 1/2 teaspoon dried thyme)
- 3 small sprigs fresh rosemary (or 1/2 teaspoon dried rosemary)
- 3 bay leaves
- 15 peppercorns (about 1/2 teaspoon)
Bread and Cheese Toppings
- 1 (1-pound) loaf of French bread, sliced into 1-inch thick slices
- 1 cup Gruyere cheese, freshly grated
- 1 cup Parmesan cheese, freshly grated
- 8 ounces Swiss cheese, sliced
- Freshly chopped chives
- Freshly cracked black pepper
Instructions
- Slice the Onions: Thinly slice about 4 large yellow onions (about 3 pounds) to yield approximately 8 cups, ensuring even caramelization and easy consumption in the soup.
- Caramelize the Onions: In a 12-inch, high-sided stainless steel pan, melt 4 tablespoons butter over medium heat. Add the sliced onions, sprinkle with 1 tablespoon kosher salt, and cayenne pepper if using. Cook, stirring occasionally, for about 10 minutes until onions turn translucent.
- Slow Caramelization: Reduce heat to medium-low and continue cooking the onions for about 90 minutes, stirring every 10-20 minutes, until they become deeply golden, sweet, and free of any raw onion bite, avoiding scorching edges.
- Prepare the Broth: In a large Dutch oven or stockpot over high heat, combine 8 cups beef broth, 2 cups water, and 1 tablespoon Better Than Bouillon Beef Base. Add the carrots, chopped onion, celery, smashed garlic, horseradish, thyme, rosemary, bay leaves, and peppercorns. Bring to a boil, then reduce to a simmer, covered with a vented lid, while onions caramelize, simmering for about 90 minutes.
- Strain the Broth: Once both the onions are caramelized and the broth has simmered sufficiently, strain the broth through a colander, discarding all solids, and return the clear, seasoned broth to the pot to keep warm.
- Add Flour and Deglaze: Sprinkle the caramelized onions with the 2 tablespoons of flour, stirring constantly and cooking for 1 to 2 minutes to eliminate any raw flour taste. Add sherry or white wine, increase heat to medium, and deglaze the pan by scraping up browned bits. Stir in fresh lemon juice and cook until most of the liquid is absorbed.
- Combine Onions and Broth: Transfer the caramelized onion mixture and any pan juices into the warm broth. Stir well, then taste and adjust seasoning with additional salt, horseradish, or herbs as desired.
- Prepare the Bread: Preheat the oven to 350°F (175°C). Slice the French bread into 1-inch thick slices. Arrange the slices in a single layer on a baking sheet and toast in the oven for 10 minutes, then flip and toast an additional 5 minutes until both sides are crisp. Optionally, lightly butter the slices before toasting for extra richness.
- Assemble the Soup: Grate the Gruyere and Parmesan cheese. Place about 1/2 tablespoon of each cheese at the bottom of 7 oven-safe bowls. Ladle the soup into the bowls, place a toasted bread slice on top of each, sprinkle generously with more Gruyere and Parmesan, and top with a slice of Swiss cheese.
- Broil and Serve: Place the filled bowls on a baking sheet and transfer to the oven rack set in the upper third. Broil on high for 2 to 4 minutes, until the cheese is melted and browned in spots. Remove carefully, garnish with freshly chopped chives and cracked black pepper, and serve hot, warning guests that the bowls will be very hot.
Notes
- Use a high-sided pan to caramelize the onions evenly and prevent splattering.
- Slow caramelization is key to developing the soup’s characteristic sweetness and depth of flavor.
- Adjust salt levels based on the type of salt used and personal preference.
- Butter the bread slices before toasting for an even richer topping, if desired.
- Be cautious when broiling the cheese-topped bowls to avoid burning.
- This soup is best served immediately while the cheese is warm and gooey.
