Name: Classic French Onion Soup Recipe
Prep time: 15 min
Cook time: 1 h
Total time: 1 h 15 min
Cuisine: French
Ingredients: 2 tablespoons olive oil; 6 medium yellow onions, sliced; 2 tablespoons butter; 1 tablespoon minced garlic; 8 cups beef broth; 1/4 cup dry sherry (optional); 1 teaspoon dried thyme; 1 teaspoon salt (or to taste); 1/2 teaspoon black pepper (or to taste); 8 slices French baguette; 2 tablespoons olive oil; 4 slices Gruyère cheese or provolone; 2 tablespoons grated Parmesan cheese

If you’ve ever craved that deeply comforting, golden-hued soup bursting with savory sweetness and topped with melty cheese, you’re in for a treat with this Classic French Onion Soup Recipe. It’s a delicious hug in a bowl that’s easier to make than you might think—stick with me, and I’ll walk you through every step.

Two white bowls filled with rich brown soup form the base layer, topped with two slices of toasted bread soaked in the soup, golden to light brown and bubbly from melted, browned cheese. The cheese layer has a creamy yellow color mixed with some crisp, darker golden spots. A small sprig of fresh green thyme is placed on top of the cheese for garnish. The bowls sit on a white marbled surface with a few scattered thyme leaves nearby. photo taken with an iphone --ar 2:3 --v 7

Jump to:

Why You'll Love This Recipe
Ingredients & Why They Work
Make It Your Way
Step-by-Step: How I Make Classic French Onion Soup Recipe
Top Tip
How to Serve Classic French Onion Soup Recipe
Make Ahead and Storage
Frequently Asked Questions:
Final Thoughts
Classic French Onion Soup Recipe

Why You'll Love This Recipe

I first made this Classic French Onion Soup Recipe on a chilly autumn night, and it instantly became one of those “go-to comfort foods” for me. The magic lies in simple ingredients treated with a bit of care and patience—plus, that golden, crispy cheese topping is irresistible.

Caramelized Onions: Slow-cooking the onions unlocks deep, sweet flavors that form the heart of every spoonful.
Rich, Savory Broth: Using beef broth and a splash of dry sherry adds layers of umami without overpowering.
Cheesy Topping: The blend of Gruyère and Parmesan broiled on the toasty baguette slices creates that perfect crispy, gooey crust you’ll look forward to every time.
Simple Ingredients, Big Flavor: Nothing fancy here—just pantry staples that come together to make something truly special.

The image shows a white ceramic bowl filled with dark brown onion soup, topped with a golden-brown melted cheese layer that covers toasted bread slices. A spoon lifts a portion from the bowl, revealing soft cooked caramelized onions with stringy, melted cheese stretching from the soup. There is a green herb sprig on the surface of the soup as garnish. The bowl is placed on a white marbled surface, and there is another similar bowl blurred in the background. Photo taken with an iphone --ar 2:3 --v 7

Ingredients & Why They Work

Each ingredient plays a starring role in this Classic French Onion Soup Recipe. From the mellow sweetness of golden onions to the rich, aromatic broth, here’s why each one matters—and a few tips for picking the best!

Flat lay of golden sliced yellow onions with their translucent layers shining softly, whole garlic cloves with papery white skins and some minced garlic scattered delicately, glossy sticks of pale butter, fresh sprigs of dried thyme with tiny green leaves, rich dark beef broth in a small glass container catching the light, crusty French baguette slices with a warm golden crust and a textured crumb, smooth pale yellow slices of Gruyère cheese slightly curled at the edges, and fine shreds of snowy white Parmesan cheese sprinkled artistically, all arranged naturally with a balance of colors and textures, placed on white marbled surface, photo taken with an iphone --ar 2:3 --v 7

Yellow Onions: Their natural sweetness intensifies beautifully when caramelized—definitely avoid white or red onions for this recipe.
Olive Oil: Helps start the cooking gently without overpowering flavors.
Butter: Adds a velvety richness that deepens the soup's flavor profile.
Garlic: Just a touch, to give warmth and depth but not steal the show.
Beef Broth: The base of your soup—opt for a good quality broth, homemade if you can, for maximum flavor.
Dry Sherry (optional): A splash adds a subtle hint of sweetness and complexity; water is fine if you skip it, but it does elevate the soup.
Dried Thyme: Classic herb pairing that complements the onions and broth.
Salt and Pepper: Season to taste—don’t forget to adjust as the soup simmers and flavors concentrate.
French Baguette: Day-old bread works best to hold up under the liquid and cheese.
Gruyère Cheese: The star of the topping—melts beautifully with a nutty flavor; provolone is a nice substitute if you’re in a pinch.
Parmesan Cheese: Adds that sharp, salty bite that perfectly balances the richness.

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Note: You'll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Make It Your Way

I love tweaking this Classic French Onion Soup Recipe to suit the mood or occasion. Whether I want it lighter or richer, it’s so flexible that you can easily put your own spin on it.

Variation: For a vegetarian version, swap the beef broth for a robust mushroom or vegetable broth and skip the sherry, which makes a surprisingly delicious twist.
Cheese Options: I sometimes sprinkle in a little mozzarella for extra gooeyness or swap Gruyère for Emmental when I want a slightly different nutty flavor.
Extra Herbs: Adding fresh rosemary or a bay leaf while simmering can add an extra layer of aroma, but don’t overpower that classic thyme taste.

Step-by-Step: How I Make Classic French Onion Soup Recipe

Step 1: Get Those Onions Nice and Caramelized

Start by heating olive oil in a large pot over medium-high heat, then toss in your sliced yellow onions. The key here is patience—cook until they’re tender, around 5-7 minutes, then lower the heat to medium-low and cook slowly for 15-25 minutes. Stir every few minutes to avoid sticking or burning. You're looking for that beautiful deep golden brown color—this step makes all the difference in flavor, so don’t rush!

Step 2: Add Butter and Garlic for More Depth

Stir in the butter and minced garlic, cooking for about 2 minutes until the butter melts and you get that lovely garlicky aroma. This step adds richness and rounds out the savory notes.

Step 3: Pour in Broth and Simmer

Pour in the beef broth and dry sherry if you’re using it. Season with thyme, salt, and pepper, then bring it all to a gentle simmer. Lower the heat and let it cook for 20-30 minutes, allowing the flavors to meld together perfectly.

Step 4: Toast the Baguette Slices

While the soup simmers, preheat your oven’s broiler. Brush both sides of your baguette slices with olive oil, lay them out on a baking sheet, and broil for 2-3 minutes per side until golden and crisp. Keep a close eye—they can burn fast!

Step 5: Assemble and Broil the Soup Bowls

Ladle the hot soup into oven-safe bowls set on a baking sheet. Layer 2 toasted baguette slices on top of each bowl. Add one slice of Gruyère cheese and sprinkle with grated Parmesan. Pop them back under the broiler for 2-3 minutes until the cheese is bubbling and turning golden brown. This is hands-down my favorite part—the cheese crust melts over the bread, locking in all the flavors.

Step 6: Serve Immediately and Enjoy

Don’t wait too long once they come out of the oven—the cheese is at its meltiest and most delicious hot! Grab a spoon and savor every bite.

Top Tip

Making classic French onion soup the right way really comes down to patience and a couple of small tricks I’ve learned through my many kitchen experiments.

Take Your Time with the Onions: It’s tempting to crank up the heat, but slow caramelization turns onions from sharp to sweet and complex.
Use Quality Broth: I always recommend at least a decent store-bought beef broth; it sets a solid flavor base that you’ll thank yourself for later.
Watch the Broiler: Cheese can go from perfect to burnt in seconds, so stay close and be ready to pull the bowls as soon as you see those golden bubbles.
Don’t Skimp on Bread: Using slightly stale baguette means your bread won’t turn to mush in the soup, it’ll get perfectly soaked yet hold shape and texture.

How to Serve Classic French Onion Soup Recipe

Garnishes

I like to keep things simple here: the broiled Gruyère and Parmesan topping is the star garnish. But sprinkling a bit of freshly chopped parsley or thyme just before serving adds a fresh pop of color and brightness that balances the richness nicely.

Side Dishes

This soup is a meal on its own, but I often pair it with a crisp green salad tossed in a lemon vinaigrette or a cheese board with some fresh fruit and nuts—anything light that contrasts the soup’s indulgence.

Creative Ways to Present

Hosting a dinner party? Serve the soup in mini crocks or French onion soup mugs for guests. You can even use individual ramekins and bake the cheese topping at the table with a mini torch for an impressive, interactive touch.

Make Ahead and Storage

Storing Leftovers

Any leftover soup stores beautifully in the fridge in an airtight container for up to 3 days. Just keep the toasted baguette and cheese toppings separate until you’re ready to reheat and serve.

Freezing

I’ve frozen this soup many times with great success—just skip the bread and cheese before freezing. When you thaw and reheat, add fresh toasted baguette and cheese to keep the texture spot on.

Reheating

Reheat gently on the stove over medium-low heat, stirring occasionally. Then add fresh toasted baguette slices and your cheese topping before broiling again to restore that golden crispness.

Frequently Asked Questions:

What kind of onions are best for Classic French Onion Soup Recipe?

Yellow onions are ideal for this recipe because of their natural sweetness, which becomes rich and caramelized during cooking. Avoid red or white onions as they have different flavor profiles that don’t caramelize as well.

Can I make this soup vegetarian?

Yes! Substitute the beef broth with a good quality vegetable or mushroom broth and omit the dry sherry if you prefer. The soup will still be deeply flavorful and comforting.

How do I prevent the cheese from burning under the broiler?

Keep a close eye on the soup while broiling, as cheese can burn quickly. I recommend staying near the oven and checking every 30 seconds once the cheese starts bubbling to catch the perfect golden brown moment.

Can I prepare the soup ahead of time?

Absolutely! Make the soup base a day or two in advance and refrigerate it. Toast the baguette slices and grate the cheese just before serving to maintain freshness and texture.

Final Thoughts

For me, this Classic French Onion Soup Recipe is one of those timeless dishes that feels like a little celebration every time I make it. It’s simple, hearty, and has that perfect balance of sweet caramelized onions and savory broth tied together with the most delicious cheesy crust. I really hope you give it a try and find as much comfort and joy in it as I do—it’s one of those recipes you’ll want to make again and again.