Get ready to wrap your hands around a bowl of pure comfort: French Onion Soup is a timeless classic that transforms humble ingredients into something truly extraordinary. This soup delivers deeply caramelized onions in a savory broth, topped with golden, gooey cheese and crisp bread for the ultimate cozy meal. It’s the kind of dish that fills your kitchen with irresistible aromas and warms you from the inside out, whether you’re serving it as an elegant starter or the main event around the dinner table.

Ingredients You’ll Need

French Onion Soup proves you don’t need fancy ingredients to achieve rich, layered flavor. Every item on this list has an important role to play, from developing a sweet onion base to achieving that signature cheesy crust. Here’s what you’ll need, plus a chef’s tip for each one to bring out the best in every bite:

Yellow onions: Sliced thin, these become wonderfully sweet and tender as they caramelize—don’t rush this step!
Unsalted butter: Adds richness and helps with even onion caramelization.
Olive oil: Prevents the butter from burning and deepens the flavor of the onions.
Beef broth (or good-quality stock): Use homemade if you have it, or choose a low-sodium, flavorful store-bought version for that classic depth.
Dry white wine: A splash brightens the onions and provides lift—leftover wine works perfectly!
Bay leaf & fresh thyme: These herbs infuse savory, woodsy notes that round out the flavor.
Baguette or crusty bread: Slightly stale bread holds up best under the broiler and soaks up just enough broth.
Gruyère cheese, shredded: Nutty, melty Gruyère is the soul of French Onion Soup’s cheesy topping—feel free to add a bit of Swiss or Emmental, too.
Salt & freshly ground black pepper: Essential for adjusting and enhancing all those savory flavors.

How to Make French Onion Soup

Step 1: Caramelize the Onions

This is where the magic begins and patience is rewarded. In a heavy pot over medium-low heat, melt butter with olive oil. Add thinly sliced onions and a pinch of salt. Stir occasionally, letting the onions slowly soften, turn golden, and eventually develop a deep, jammy brown color. Expect this step to take up to 45 minutes, but the transformation is worth every minute.

Step 2: Deglaze and Build Flavor

Once your onions are a rich, even brown, add the dry white wine to the pot. Scrape the bottom to dissolve all those caramelized bits—they’re pure flavor! Let the wine simmer off for a few minutes, intensifying the sweetness and complexity of the onions.

Step 3: Simmer the Soup

Pour in the beef broth, then toss in the bay leaf and a few sprigs of fresh thyme. Simmer gently for about 20–30 minutes to let all the flavors meld and deepen. Taste and adjust with salt and pepper. Don’t forget to remove the herbs before serving.

Step 4: Toast the Bread

Slice your baguette and toast the rounds under the broiler or in a toaster until golden and crisp. This step ensures that your bread stands up to the bubbly cheese and won’t go too soggy in the soup.

Step 5: Broil the Cheesy Topping

Ladle hot French Onion Soup into oven-safe bowls, top each with a toasted bread round, and mound with shredded Gruyère. Place the bowls under the broiler until the cheese is melted, bubbling, and lightly browned. It’s irresistibly aromatic and looks as gorgeous as it tastes!

How to Serve French Onion Soup

Garnishes

The classic finish is a sprinkle of extra thyme or chopped chives, but a twist of fresh cracked pepper or a tiny drizzle of olive oil adds a restaurant-worthy touch. Don’t forget to set out extra cheese on the side for those who want to go all in.

Side Dishes

French Onion Soup is rich and satisfying, so pair it with a crisp green salad tossed in a simple vinaigrette to keep things bright. A platter of mixed olives or a small charcuterie board also makes a lovely, casual French bistro-style meal.

Creative Ways to Present

Try serving your French Onion Soup in mini cocottes for an elegant dinner party touch, or bake individual portions in small mason jars for a rustic, picnic-style vibe. For a playful twist, turn the soup into crostini—pile caramelized onions and cheese on crusty bread slices, then broil until bubbly.

Make Ahead and Storage

Storing Leftovers

Let leftover French Onion Soup cool to room temperature, then store in an airtight container in the refrigerator for up to 4 days. Keep the bread and cheese separate to keep them from turning soggy.

Freezing

The soup base freezes beautifully: ladle cooled soup (without bread or cheese) into freezer-safe containers, leaving a little room for expansion. Freeze for up to 3 months. Thaw overnight in the refrigerator before reheating.

Reheating

Gently reheat French Onion Soup on the stovetop over medium heat until hot. Toast fresh bread, assemble in oven-safe bowls, add cheese, and broil as originally directed for that just-made finish. Leftovers never tasted so decadent!

FAQs

Can I make French Onion Soup vegetarian?

Absolutely! Swap out the beef broth for a rich vegetable broth and consider adding a splash of soy sauce or a few dried mushrooms to boost the umami factor. You’ll still get loads of depth and comfort in every spoonful.

What kind of onions work best?

Yellow onions are a classic choice for French Onion Soup thanks to their sweetness and versatility, but you can also blend in a few red or sweet onions for extra complexity. Avoid white onions, as they tend to be sharper and less flavorful when caramelized.

How do I keep the bread from getting soggy?

Toasted, day-old baguette slices hold up best in the soup, especially when broiled with cheese on top. If you like your bread very crisp, use a thick slice and broil just until the cheese melts, serving right away.

Is there a substitute for Gruyère cheese?

If Gruyère isn’t available, try Swiss, Emmental, or even a sharp provolone. Each will melt nicely and deliver that signature bubbly, golden crust.

Can I make French Onion Soup ahead of time for a crowd?

Definitely! Prepare the soup base a day or two ahead and refrigerate. Before serving, reheat the soup, toast the bread, and broil each portion with cheese. It’s a surefire way to impress a table full of hungry guests with minimal last-minute stress.

Final Thoughts

Few dishes offer as much satisfying flavor for the effort as French Onion Soup. It’s inviting, a little bit special, and wonderfully heartwarming—the very definition of comfort food. Grab a pot, some onions, and treat yourself (and someone lucky) to this unforgettable classic at home!

French Onion Soup Recipe