In this French Onion Soup, sweetly caramelized onions simmer with savory beef broth, garlic, and thyme to create a richly aromatic base. The bold flavors are complemented by a crisp toasted baguette covered in melted Gruyere cheese, offering a comforting, soul-warming dish that’s both indulgent and satisfying.

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I’ve spent a lot of time testing different methods before I landed on this Best French Onion Soup recipe and let me tell you, it really is amazing. I start with 6 large yellow onions, thinly sliced, and use 3 tbsp unsalted butter along with 1 tbsp olive oil to properly caramelize them over low heat.

Then I add minced garlic and a bit of sugar to help bring out the flavour, and a splash of dry white wine gives it a wonderfully rich aroma. With 6 cups of beef broth, 2 bay leaves and a few sprigs of fresh thyme simmering away, the aroma fills your kitchen with anticipation.

I finish it off with toasted French baguette slices and 2 cups of grated Gruyere cheese that melt into a gooey, delicious topping. This soup not only warms you from the inside out, but its nutritional value makes it a hearty comfort food meal that’s perfect for dinner.

Why I Like this Recipe

I love how the onions get slowly caramelized until they’re deep golden brown because that gives the soup a really rich, sweet flavor that sticks with me all day. I also like that the recipe uses simple ingredients that come together in a way that makes the soup feel both fancy and super easy to make. The crunchy toasted baguette with the melted Gruyere cheese on top adds an awesome texture contrast that i just can’t get enough of. Plus, every time i make it i feel like i’m making something truly comforting and satisfying—like a warm hug on a chilly day.

Ingredients

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Onions are fiber rich, naturally sweet, and develop deep caramel flavors while cooking.
Garlic offers a pungent burst that enhances umami, vitamins, and slight spiciness.
Beef broth gives hearty protein and umami flavor, though it can be sodium heavy.
Unsalted butter adds creaminess and depth without extra salt, while boosting flavor.
Olive oil for cooking adds subtle fruity flavor and a smooth texture.
Baguette provides carbs that toast up crispy and soak up all the savory soup.
Gruyere cheese melts into silky, nutty, protein-packed goodness that brings classic richness.
Sugar provides a touch of sweetness that helps enhance the onions’ caramelization.
Bay leaves impart subtle herbal notes, balancing the deep flavors of the broth.

Ingredient Quantities

6 large yellow onions, thinly sliced

3 tbsp unsalted butter

1 tbsp olive oil

1 tsp salt

1/2 tsp sugar (helps with the caramelization, optional)

3 cloves garlic, minced

1/4 cup dry white wine

6 cups beef broth

2 bay leaves

A few sprigs of fresh thyme or 1 tsp dried thyme

1 French baguette, sliced and toasted

2 cups grated Gruyere cheese

How to Make this

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1. Slice your 6 large yellow onions thinly and set aside.

2. In a large pot, heat 3 tablespoons of unsalted butter with 1 tablespoon olive oil over medium heat.

3. Add the sliced onions along with 1 teaspoon salt and 1/2 teaspoon sugar (if using) and cook them slowly, stirring frequently for about 45 minutes until they’re deep golden brown and nicely caramelized.

4. Stir in 3 minced garlic cloves and cook for another minute until fragrant.

5. Pour in 1/4 cup dry white wine to deglaze the pot, scraping up all those delicious brown bits from the bottom.

6. Add 6 cups beef broth, 2 bay leaves, and a few sprigs of fresh thyme (or 1 teaspoon dried thyme) and bring the mixture to a gentle simmer.

7. Let the soup simmer for 30 minutes so all the flavors meld together, stirring occasionally.

8. Meanwhile, slice a French baguette and toast the slices until they’re crisp.

9. When the soup is ready, ladle it into ovenproof bowls, top each with a toasted baguette slice, and generously sprinkle 2 cups of grated Gruyere cheese over the top.

10. Place the bowls on a baking sheet and put under a preheated broiler for a few minutes until the cheese is melted and bubbly. Let it cool a bit before serving. Enjoy your comforting bowl of French Onion Soup!

Equipment Needed

1. Chef’s knife
2. Cutting board
3. Large, heavy-bottomed pot
4. Wooden spoon for stirring
5. Measuring cups and spoons
6. Bread knife for slicing the French baguette
7. Toaster or oven to toast the baguette slices
8. Ladle for serving the soup
9. Ovenproof bowls
10. Baking sheet
11. Oven with a broiler setting

FAQ

Q: How do I know when my onions are caramelized enough?

A: When the onions are a deep golden brown and really soft. It normally takes around 45 to 60 minutes so keep an eye on them and stir now and then.

Q: Can I use a different type of broth than beef?

A: Yes, you can try chicken broth if you want a lighter flavor but beef broth really gives it that rich, hearty taste.

Q: Is the sugar really necessary in this recipe?

A: The sugar is optional but it helps the onions caramelize faster and brings out more of their natural sweetness.

Q: May I use dried herbs instead of fresh herbs?

A: Sure, you can use dried thyme instead of fresh. Just use a bit less since dried herbs are usually more potent.

Q: How should I store any leftover soup?

A: Let the soup cool down a little then store it in an airtight container in the fridge for up to 3 days. When reheating, do it over low heat slowly.

BEST French Onion Soup Recipe Substitutions and Variations

Instead of unsalted butter, you can try using margarine or even a small amount of olive oil for a lighter flavor sometimes
If you dont have extra olive oil, any neutral vegetable oil like canola works just fine
Dry white wine can be swapped with dry vermouth or simply a bit more beef broth if you dont have any wine on hand
Beef broth can be substituted with beef bouillon cubes dissolved in water if you are in a pinch
If you cant find Gruyere cheese, melted swiss cheese or even a mild cheddar can do the trick pretty well

Pro Tips

1. When caramelizing the onions, be patient and keep the heat on medium low so they slowly turn a golden brown. If you rush it, you may end up with burnt onions instead of that rich deep flavor that makes the soup awesome.

2. Make sure to scrape up all those brown bits from the bottom when you deglaze with the white wine. Those little bits are packed with flavor and really add to the overall taste of the soup.

3. Let the soup simmer a bit longer if you can. Giving it extra time to marry all the flavors can really make a difference, even if it means waiting a little longer before serving.

4. When you toast your baguette slices, try brushing them with a little olive oil or butter beforehand. It helps them crisp up really well and gives a tastier crunch when you top the soup with them, so your cheese melts on top perfectly.