French Onion Soup is pure comfort in a bowl—a timeless, deeply savory French classic where the simplest ingredients transform into a rich, golden elixir. There’s nothing quite like that first spoonful: the sweet tang of caramelized onions, the deeply flavorful broth, and a blanket of gooey, bubbling cheese atop a garlicky, toasty baguette. Whether you’re warding off a winter chill or simply craving a bowl of something magnificent, this soup never fails to make an ordinary meal feel celebratory.
Ingredients You’ll Need
This French Onion Soup recipe proves that truly great food doesn’t need a long shopping list—just quality, everyday ingredients treated with patience. Each element is essential, from the onions’ caramel sweetness to the nutty bite of Gruyère, coming together for layers of irresistible flavor.
- Yellow onions: The star ingredient brings sweetness and depth of flavor once fully caramelized—slice them thinly for even cooking.
- Unsalted butter: Adds richness and helps the onions break down gently without browning too quickly.
- Olive oil: Prevents the butter from burning and adds a subtle fruity undertone.
- Salt: Draws moisture from the onions so they caramelize more evenly and grows the flavor base.
- Sugar: Speeds up caramelization, coaxing out the onions’ natural sweetness.
- Fresh thyme leaves: Infuses the soup with an herby, floral note; dried thyme works in a pinch.
- Garlic: Just a hint for gentle pungency and backbone.
- Dry white wine (optional): Lifts the flavor and helps deglaze the pan, scraping up all those caramelized bits.
- Beef broth (low-sodium): The heart of the soup—look for high-quality broth or make your own for best results.
- Worcestershire sauce: Adds a complex umami depth that makes the broth sing.
- Salt and black pepper: For seasoning every layer to taste.
- Baguette: Slices become the signature cheesy croutons; day-old bread is perfect here.
- Gruyère or Swiss cheese: Shredded on top, it melts to golden, bubbling perfection.
How to Make French Onion Soup
Step 1: Caramelize the Onions
Start with a sturdy Dutch oven or heavy-bottomed pot to ensure slow, even caramelizing—this is the foundation of classic French Onion Soup. Melt the unsalted butter and olive oil over medium heat, then add all those mountains of sliced onions, a sprinkle of salt, and sugar. As you stir, the kitchen will fill with the sweetest, most inviting aroma. Don’t rush this part: cook gently for 30 to 40 minutes, stirring often, as the onions transform from opaque to golden, then finally to that deep, jammy brown. Adjust the heat down if they brown too quickly; patience rewards you with that deep, layered flavor French Onion Soup is famous for.
Step 2: Build the Flavors
Once your onions are lusciously caramelized and almost sticky, stir in the minced garlic and thyme. Let them sizzle for about a minute until fragrant—it’s a tiny moment that adds so much to the final spoonful. If you’re using wine, now’s the time: pour it in and scrape up all the dark bits stuck to the bottom (flavor gold!). Simmer for a couple of minutes until the wine is mostly cooked off but has relaxed the mixture and deepened the taste.
Step 3: Simmer with Broth
Add the beef broth and Worcestershire sauce to the pot, giving everything a good stir to blend. Bring the soup to a gentle simmer, then reduce the heat to low and allow it to cook, uncovered, for another 20 to 25 minutes. This step lets all the flavors meld into something even greater than the sum of their parts—taste and adjust salt or pepper as needed to hit that perfect savory balance.
Step 4: Toast the Baguette Slices
While your soup simmers away, turn your attention to the baguette. Preheat the broiler and arrange the slices on a baking sheet. Toast for 1 to 2 minutes per side until crisp and golden—the perfect vehicle for all that melted cheese. These toast rounds should be sturdy enough to hold up in the finished French Onion Soup without dissolving.
Step 5: Finish and Broil
Ladle the hot soup into broiler-proof bowls, nestling a toasted baguette slice (or two) on each. Pile on a generous handful of grated Gruyère or Swiss cheese, making sure some spills onto the edges for extra crispy bits. Slide the bowls under the broiler for 2 to 3 minutes, keeping a close eye as the cheese bubbles and turns golden. This final flourish takes French Onion Soup from great to utterly unforgettable!
How to Serve French Onion Soup
Garnishes
A finishing sprinkle of fresh thyme or a crack of black pepper makes each bowl of French Onion Soup restaurant-worthy. If you have a few extra caramelized onions, float them on top before the cheese for added lusciousness. For a French bistro-style touch, try a drizzle of olive oil or even a whisper of good balsamic vinegar.
Side Dishes
French Onion Soup is rich and hearty, so pair it with something fresh and light. A crisp green salad with a simple vinaigrette, steamed haricots verts, or thinly sliced apples dressed with lemon are all classic choices. If you’re serving a crowd, an extra basket of crusty bread never goes amiss.
Creative Ways to Present
Impress guests or treat yourself by serving French Onion Soup in individual oven-safe crocks or even as part of a flight of small soup tastings. For gatherings, make mini versions in espresso cups or shot glasses—each bite boasting its own cheesy crouton. This soup is also sensational served alongside a mini grilled cheese for the ultimate comfort duo.
Make Ahead and Storage
Storing Leftovers
If you find yourself with leftover French Onion Soup (lucky you!), let it cool to room temperature first. Store it in an airtight container in the refrigerator for up to four days. Keep the toasted bread and cheese separate so they don’t get soggy before reheating.
Freezing
French Onion Soup base (without bread or cheese) freezes beautifully. Pour cooled soup into individual containers or a freezer bag, and freeze for up to three months. When you’re ready to enjoy, thaw overnight in the refrigerator. For best results, always add fresh baguette and cheese just before serving.
Reheating
To reheat, warm the soup gently on the stovetop over medium-low heat, stirring occasionally. Ladle hot soup into oven-safe bowls, top with fresh toasted bread and cheese, then broil just until the cheese is bubbly. This way, every serving will taste as good as day one!
FAQs
Can I make French Onion Soup vegetarian?
Absolutely! Simply swap the beef broth for a high-quality vegetable broth and either omit the Worcestershire sauce or use a vegan alternative/soy sauce. You’ll still get wonderful depth and savoriness without any meat.
What kind of onions work best?
Classic yellow onions are traditional for French Onion Soup, thanks to their balance of sweet and savory flavors. For a twist, try mixing yellow and red onions or even sweet Vidalia onions for a milder, gentler soup.
Why does caramelizing the onions take so long?
Low and slow is the key for this recipe—the magic happens in the extended cooking time, which draws out maximum sweetness and deepens each layer of flavor. Rushing this step can result in burnt or bitter onions, so enjoy the delicious anticipation!
Do I need special bowls?
Oven-safe bowls or crocks are traditional (and help you get that glorious melted cheese top!), but if you don’t have them, you can toast the bread with cheese separately and float it on the soup before serving. Still delicious, just a bit less dramatic.
Can I use a different cheese?
Gruyère is the classic choice because it melts beautifully and boasts a nutty, creamy flavor. However, Swiss cheese, Emmental, or even a robust provolone or mozzarella work in a pinch—choose something that melts well and you love.
Final Thoughts
If there’s one soup that truly feeds the soul, it’s French Onion Soup. The time you spend coaxing those onions to a golden jam is rewarded a hundred times over with every luscious spoonful. Don’t wait for a special occasion—treat yourself or someone you love to this iconic bowl soon. You won’t regret it!
Print
French Onion Soup Recipe
- Prep Time: 15 minutes
- Cook Time: 1 hour
- Total Time: 1 hour 15 minutes
- Yield: 4 servings
- Category: Soup
- Method: Stovetop, Broiling
- Cuisine: French
- Diet: Non-Vegetarian
Description
Warm up with a bowl of classic French Onion Soup topped with melted cheese and a crispy baguette slice. This comforting soup is perfect for a cozy dinner or lunch.
Ingredients
Onion Mixture:
- 4 large yellow onions (thinly sliced)
- 3 tbsp unsalted butter
- 1 tbsp olive oil
- 1 tsp salt
- ½ tsp sugar
- 1 tsp fresh thyme leaves (or ½ tsp dried)
- 2 cloves garlic (minced)
- ½ cup dry white wine (optional)
Soup Base:
- 6 cups beef broth (low-sodium)
- 1 tbsp Worcestershire sauce
- Salt and black pepper to taste
For Serving:
- 1 baguette (sliced)
- 1 ½ cups grated Gruyère or Swiss cheese
Instructions
- Caramelize Onions: In a large pot, cook onions, butter, olive oil, salt, and sugar until golden.
- Add Flavor: Stir in thyme and garlic, then deglaze with wine.
- Simmer: Pour in broth, Worcestershire sauce, simmer for flavor development.
- Prepare Toppings: Toast baguette slices, top with cheese.
- Broil: Ladle soup into bowls, top with bread and cheese, broil until bubbly.
Notes
- Use sweet onions for a milder flavor or a mix of yellow and red onions for depth.
- For a vegetarian version, use vegetable broth and skip the Worcestershire sauce or replace with soy sauce.
