French Onion Soup

French Onion Soup is one of those timeless recipes that feels special every single time you make it. Sweet caramelized onions simmer slowly in rich beef broth until the flavor deepens and turns beautifully savory. I like to use my own Homemade Beef Bone Broth for this recipe — it makes all the difference.

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A good French Onion Soup truly depends on the broth because it’s the heart of the recipe. Using a flavorful, slow-simmered beef broth or bone broth gives every spoonful that deep, rich taste and velvety texture. If you’ve never made your own, I highly recommend giving it a try. You can find my recipe for Homemade Beef Bone Broth here — it’s simple, nourishing, and adds an incredible boost of flavor to this classic, RIDIC-ULICIOUS soup.

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Why You’ll Love This Recipe

This French Onion Soup is comforting, flavorful, and simple to make. The caramelized onions give it that deep, savory base, while the melted cheese and toasted bread cubes add the perfect texture in every bite. Switching to bread cubes instead of a single slice makes the soup so much easier to eat — you can scoop up the cheese, bread, and broth together without fighting the spoon!

• Rich, deep flavor: Slowly caramelized onions and good-quality broth create a restaurant-worthy taste.
• Cheesy perfection: The toasted bread cubes and gooey mozzarella make every spoonful irresistible.
• Pure comfort food: Cozy, melty, and perfect for chilly nights.

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Ingredients You’ll Need

For the Soup:

• 8–9 cups sliced yellow onions (about 4 large)
• 3 tablespoons butter
• 1 tablespoon olive oil
• 1 teaspoon sugar (to help caramelize the onions)
• 1 teaspoon salt
• 1/2 teaspoon black pepper
• 2 garlic cloves, minced
• 1/2 cup dry white wine (optional, for deglazing)
• 6 cups beef broth or homemade beef bone broth
• 1 teaspoon Worcestershire sauce
• 1 bay leaf
• 1 teaspoon fresh thyme (or 1/2 teaspoon dried)

For Serving:

• 3 cups cubed baguette or crusty bread (1-inch cubes)
• 2 tablespoons olive oil
• 1 1/2 cups shredded mozzarella cheese

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About the Onions

You’ll want about 8 to 9 cups of sliced onions, which comes from roughly 4 large yellow onions. Yellow onions are my go-to for this soup because they caramelize beautifully and give that perfect balance of sweetness and savory depth.

If you’d like to experiment:

• Sweet onions (like Vidalia or Walla Walla) will make your soup a little milder and sweeter.
• White onions will create a sharper, more savory edge.
• Red onions can work in a pinch, but they’ll change the soup’s color and add a hint of tang.

For the most classic flavor — and the one you’ll find in cozy bistros — yellow onions are definitely the best choice.

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Step-by-Step Instructions

1. Caramelize the Onions

In a large Dutch oven, melt butter and olive oil over medium heat. Add the sliced onions, sugar, salt, and pepper. Stir occasionally and cook for 25–30 minutes until the onions turn a deep golden brown. This slow caramelization gives the soup its rich, sweet flavor — don’t rush this step!

2. Add Garlic and Deglaze

Once the onions are caramelized, stir in the minced garlic and cook for about a minute. Pour in the wine (if using) to deglaze the pan, scraping up any browned bits — those bits are packed with flavor.

3. Add Broth and Seasonings

Stir in the beef broth, Worcestershire sauce, bay leaf, and thyme. Bring to a simmer, then reduce the heat and cook gently for 20–25 minutes. Remove the bay leaf before serving.

4. Toast the Bread Cubes

Preheat your oven to 375°F. Toss the cubed bread with olive oil and spread on a baking sheet. Toast for 10–12 minutes, stirring halfway through, until golden and crisp. These cubes will hold their texture beautifully when added to the soup.

5. Broil the Cheese Topping

Ladle the hot soup into oven-safe bowls. Add a handful of toasted bread cubes to each bowl and sprinkle generously with shredded mozzarella. Broil for 2–3 minutes, just until the cheese is melted and bubbly.

6. Serve Warm and Enjoy

Carefully remove the bowls from the oven — they’ll be hot! Serve immediately and enjoy every cheesy, savory bite.

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Tips for Success

• Use a heavy pot: A Dutch oven distributes heat evenly and helps caramelize the onions perfectly.
• Don’t skimp on the broth: The broth is the heart of the soup. Try my Homemade Beef Bone Broth for the best flavor.
• Make it ahead: The soup base can be made a day or two ahead. Just reheat and add the bread and cheese before broiling.

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What to Serve with French Onion Soup

This soup can shine as a cozy main course or a hearty starter. Serve it with:

• A simple green salad with balsamic vinaigrette
• Roasted vegetables or grilled asparagus
• A side of garlic bread or a crusty baguette

It also pairs beautifully with steak or roast beef dinners for a comforting, bistro-style meal.

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FAQ

Can I use a different cheese?

Yes! While mozzarella melts beautifully, Gruyère or Swiss cheese will give you a more traditional French onion flavor with a nutty finish.

Can I make this soup vegetarian?

You can substitute vegetable broth, but the flavor won’t be quite as deep. For a richer taste, add a splash of soy sauce or a spoonful of miso paste.

How do I store leftovers?

Store cooled soup (without bread or cheese) in an airtight container in the refrigerator for up to 3 days. Reheat on the stovetop and top with fresh bread and cheese before broiling.

FOODIE & GRILLER APPAREL

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