French Onion Soup

French Onion Soup is a classic, soul-warming dish made with deeply caramelized onions, rich broth, and toasted bread smothered in melted cheese. This savory soup is cozy, comforting, and full of depth, making it one of my favorite meals to enjoy on a cold day. The blend of sweet onions and savory broth topped with cheesy, crispy bread is simply irresistible.

Why You’ll Love This Recipe

I love this recipe because it brings restaurant-quality flavor to my kitchen with just a few simple ingredients. The slow caramelization of onions transforms them into something sweet, rich, and deeply flavorful. Topped with crusty bread and gooey melted cheese, it turns into a complete, satisfying dish that feels both rustic and elegant.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

• Yellow or sweet onions (thinly sliced)

• Olive oil and/or butter

• Garlic (minced)

• Salt and pepper

• Fresh thyme (or dried thyme)

• Bay leaf

• All-purpose flour (for thickening, optional)

• Vegetable or beef broth (use your favorite)

• Baguette or crusty bread (sliced and toasted)

• Gruyère cheese (shredded) or another melty cheese like mozzarella or Swiss

Directions

1. I heat olive oil and butter in a large pot over medium heat. I add the sliced onions and cook slowly, stirring often, until they’re deeply golden and caramelized—about 30–40 minutes.

2. I stir in the garlic and thyme, then sprinkle a bit of flour if I want a thicker soup, and cook for another minute.

3. I add the broth and bay leaf, bring everything to a simmer, and let it cook for 15–20 minutes so the flavors blend.

4. I season with salt and pepper to taste and remove the bay leaf.

5. While the soup simmers, I toast slices of baguette until golden and crisp.

6. I ladle the soup into oven-safe bowls, top with a piece of toast, and sprinkle a generous amount of cheese on top.

7. I place the bowls under the broiler until the cheese is melted and bubbling, then let them cool slightly before serving.

Servings and timing

This recipe serves 4 to 6 people. It takes about 15 minutes to prep and around 1 hour to cook, so it’s ready in roughly 75 minutes total.

Variations

Sometimes I add a splash of balsamic vinegar for extra depth or use vegetable broth to keep it vegetarian. I’ve also topped it with a mix of cheeses like provolone and parmesan when I want extra richness. For a gluten-free version, I use GF bread and skip the flour.

Storage/reheating

I store the soup (without the bread and cheese topping) in the fridge for up to 4 days. To reheat, I warm it on the stove and toast fresh bread with cheese when serving. The soup also freezes well—I let it cool completely and freeze in airtight containers for up to 2 months.

FAQs

What’s the best onion to use?

I use yellow or sweet onions for the best flavor. A mix of different onions also works well if I want complexity.

How do I get perfect caramelized onions?

I cook them low and slow, stirring often, and let them reduce until they’re golden brown and soft. It takes patience but it’s worth it.

Can I make it vegetarian?

Yes, I use vegetable broth and skip any meat-based toppings. The flavor still turns out rich and savory.

What if I don’t have oven-safe bowls?

I toast the bread with cheese separately and float it on top of the soup just before serving.

What’s the best cheese to use?

Gruyère is the traditional choice for its meltability and flavor, but Swiss, mozzarella, or a sharp white cheddar also work.

Conclusion

French Onion Soup is a timeless comfort food that delivers big flavor from simple ingredients. From the slow-cooked onions to the cheesy bread topping, it’s a meal that feels cozy, satisfying, and totally indulgent. Whether I’m making it for a quiet dinner or sharing it with friends, it’s always a classic I come back to.