Few dishes capture the heart of French cuisine quite like Classic French Onion Soup. With its rich caramelized onions, deep beef broth, and golden, cheesy bread floating on top, this timeless recipe brings warmth, comfort, and sophistication to your table. Whether you’re preparing it on a chilly autumn evening or looking to impress guests at your next dinner party, this classic dish delivers both elegance and soul.

Let’s dive into the art of making this beautifully layered soup — from perfectly caramelized onions to that irresistible blanket of melted Gruyère cheese.

I love a good bowl of soup during the colder months! Some people are soup people year round – but not me. I want a hot bowl of soup when it’s cold or snowing. Don’t get me wrong, you can have this classic French Onion soup any time! I’m just part of the small percent of people who prefer hot soups when the weather is cool.

What is classic French Onion soup?

French Onion Soup, or Soupe à l’oignon gratinée, has humble beginnings. Originally considered peasant food, it was made to stretch a few simple ingredients — onions, bread, and broth — into something hearty and filling. Over time, French chefs elevated it into a refined dish, transforming slow-cooked onions into a deep, flavorful base and adding toasted bread topped with gooey cheese. Today, it’s a beloved comfort food found in brasseries across Paris and beyond.

French Onion Soup Ingredients

To make an authentic French Onion Soup, start with quality ingredients — each one plays an important role in building layers of flavor. Here’s what you’ll need:

• yellow onions, thinly sliced
• butter
• olive oil
• garlic
• dry white wine
• beef stock
• bay leaves
• dried thyme
• Salt and pepper
• baguette
• Gruyère cheese

Each ingredient is classic — nothing fancy or fussy. The magic lies in the method.

How to make classic French Onion soup

? Step 1: Slice and Prepare the Onions

The heart of this soup is, of course, the onions. Begin by peeling and thinly slicing 2.5 pounds of yellow onions. Try to keep the slices even so they cook uniformly. Yellow onions are ideal for this dish because they caramelize beautifully, turning sweet and golden without becoming overly soft.

? Step 2: Caramelize the Onions

This step is where patience pays off. In a large pot or Dutch oven, melt the butter with the olive oil over medium heat. Add your sliced onions and stir until they’re coated in the butter mixture.

Cook them for about 15 minutes, stirring often, until the onions begin to soften and turn translucent.

Next, reduce the heat to medium-low and continue cooking for 30–40 minutes, stirring occasionally. The onions will gradually transform from pale and soft to deeply golden brown and jammy. This is where the flavor builds — don’t rush it!

In the last few minutes, add your minced garlic and cook gently, making sure it doesn’t burn. The aroma at this stage is incredible — rich, sweet, and savory all at once.

? Step 3: Deglaze and Simmer

Once your onions are perfectly caramelized, it’s time to deglaze the pot. Turn the heat up to medium-high and pour in 1/2 cup of dry white wine. Use a wooden spoon to scrape up all those flavorful browned bits stuck to the bottom of the pot. Those bits are pure flavor gold.

Let the wine simmer and reduce by about half, which should take roughly 5 minutes. This deepens the flavor and balances the sweetness of the onions with a gentle acidity.

Now, add your 6 cups of beef stock, 2 bay leaves, and 1/2 teaspoon of dried thyme. Season lightly with salt and black pepper.

Bring everything to a gentle simmer, then reduce the heat to low and let it bubble away for about 30 minutes. This gives the soup time to meld into something truly special — rich, savory, and deeply comforting.

Before serving, remove the bay leaves.

? Step 4: Toast and Broil the Baguette

While the soup simmers, prepare the topping that makes French Onion Soup so iconic: the cheesy bread.

Preheat your broiler and place 8 slices of baguette on a baking sheet. Toast them lightly on both sides. Then, top each slice with grated Gruyère cheese — about 1 cup in total — and broil just until the cheese is bubbly and golden, around 2–3 minutes. Keep a close eye on them; broilers can go from perfect to burnt in seconds!

? Step 5: Serve and Enjoy

Once the soup is ready, ladle it into individual bowls. Carefully float a cheesy baguette slice (or two!) on top of each bowl. The heat from the soup will slightly melt the cheese, blending everything together in perfect harmony.

Serve immediately — and take a moment to appreciate that first spoonful. The sweetness of caramelized onions, the depth of the broth, and the creamy Gruyère create a flavor that’s both nostalgic and luxurious.

? Tips for Perfect French Onion Soup

1. Use patience when caramelizing. This is the most important step. Low and slow heat brings out the natural sugars in the onions, giving the soup its signature sweetness and color.
2. Choose the right wine. A dry white wine like Sauvignon Blanc or Pinot Grigio works best, adding just the right touch of acidity. Don’t buy a whole bottle just for this recipe though! Extra beef broth will work just fine!
3. Don’t skip the deglazing. Scraping up the browned bits adds incredible flavor depth.
4. Homemade broth makes a difference. While store-bought stock works fine, a rich homemade beef stock will elevate the soup to restaurant quality.
5. Gruyère is traditional — but flexible. If you can’t find it, try Swiss or Comté cheese for a similar nutty flavor.

?? Make-Ahead and Storage

French Onion Soup actually tastes even better the next day. The flavors deepen and mellow overnight, so it’s a fantastic make-ahead option. Simply reheat on the stove over low heat.

If you’re storing leftovers, keep the soup and bread separate. The soup will last up to 4 days in the refrigerator or can be frozen for up to 3 months. When ready to serve, reheat and top with freshly broiled cheese to restore that signature texture.

Other Soup Recipes to Try

Looking for other soup recipes that will warm you up? Check out these other classic soup recipes:

• Crock Pot Loaded Potato Soup
• Broccoli Cheese Soup
• Chicken Tortilla Soup
• Slow Cooker Stuffed Pepper Soup
• One Pot Lasagna Soup

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