French Onion Soup

My French Onion Soup is rich, deeply savory, and finished with toasted French bread and bubbling melted Gruyère. After 30 years of marriage to a man who has loved this soup since childhood, I can tell you this recipe had to be perfect. It took a lot of testing, but this version finally nails it every single time.

 

My Classic French Onion Soup

My husband is the youngest of five kids with a 10-year gap between him and the closest sibling. Since he was essentially an only child, his parents took him to a lot of nice restaurants growing up, and French onion soup was always his order. He’s been a connoisseur since before most kids knew what an appetizer was. Needless to say, I had a lot of expectations to live up to whenI started developing this recipe.

We have eaten a lot of French onion soup together over the years. (We even ordered it on a tripto Paris, only to discover it’s not called French onion soup in France. It’s just onion soup. The joke was on us.) 

After all of that tasting and testing, this is the version that finally got the stamp of approval. The caramelized onions are deep and sweet, the broth is rich and savory, and the cheese on top is exactly as golden and bubbly as it should be.

I want to be upfront: this recipe takes about an hour, and most of that time is the onions. You can’t rush caramelized onions. But the good news is that most of it is hands-off. You just let the onions do their thing while the stock warms, and the rest comes together quickly. 

For more comforting soup recipes, check out my Tomato Soup, Chicken Noodle Soup, Potato Soup, and Broccoli Cheddar Soup

Why My French Onion Soup is the Best

• Deeply caramelized onions – 40 to 45 minutes of slow cooking transforms the onions into something sweet, silky, and full of flavor. This is the step that separates a great French onion soup from a mediocre one.
• White wine and sherry – these two additions build layers of flavor that make the soup taste like it came from a restaurant. Easy substitutions are included if you prefer not to cook with alcohol.
• Broiled Gruyère on top – melted, bubbly cheese over toasted French bread is the signature finish that makes this soup unforgettable. I’ve included Swiss as an easy swap,but Gruyère is worth finding.

French Onion Soup Ingredients

• Yellow onions – Yellow onions are the classic choice because they caramelize beautifully and have the right balance of sweetness and savory flavor.
• Butter – Butter helps the onions soften and caramelize slowly, adding richness to the base.
• Salt – Added at the start to draw moisture out of the onions and help them soften faster.
• Beef stock – The backbone of the soup. Use a good-quality stock because it makes a real difference in the final flavor.
• Garlic – Adds depth and a savory layer underneath the sweetness of the onions.
• White wine – Deglazes the pan and brightens the flavor. See the substitutions section if you prefer to leave it out.
• Sherry – Just a small amount adds a richness and complexity that makesthe soup taste truly special. Substitute listed below.
• All-Purpose Flour – Stirred in after the wine to lightly thicken the soup.
• Worcestershire sauce – Adds a savory, umami depth that rounds out the broth.
• Fresh thyme – Adds herbal warmth. Dried thyme works in a pinch; just use half the amount.
• Bay leaf – Simmers with the soup for added depth of flavor. Remove before serving.
• Pepper – Freshly ground black pepper is best here.
• French bread – The bread soaks up the soup from below and holds up beautifully under the melted cheese.
• Gruyère or Swiss cheese – Gruyère is the classic choice and melts into a golden, bubbly crust. Swiss is a great, easy-to-find substitute

Substitutions or Variations (don’t have to include)

• No sherry? Use 1 teaspoon apple cider vinegar plus 2 teaspoons beef stock as a substitute.
• No white wine? Swap in 1/2 cup additional beef stock.
• No Gruyère? Swiss cheese melts just as well and is easy to find at most grocery stores.

How to Make French Onion Soup

1. Peel and thinly slice the onions.
2. Melt butter in a large Dutch oven over medium heat. Add the onions and salt, cover, and cook for 5 minutes until softened.
3. Remove the lid and cook the onions, stirring frequently, for 40 to 45 minutes until they are deeply caramelized and golden brown.

4. While the onions cook, heat the beef stock in a separate pot and keep it warm.
5. Add the garlic, white wine, and sherry to the onions and bring to a boil.
6. Stir in the flour and cook for 1 to 2 minutes until the onions are coated.

4. Add the warm stock, Worcestershire sauce, thyme, bay leaf, and pepper. Simmer for 10 to 15 minutes.
5. Preheat your oven to 400° F and toast the French bread slices until golden.
6. Remove the bay leaf and ladle the soup into oven-safe bowls. Top each bowl with 2 slices of toasted bread and a generous amount of shredded cheese.
7. Broil until the cheese is melted and bubbly. Serve immediately.

What to Serve with French Onion Soup

French Onion Soup is hearty enough to serve as a first course or a light dinner on its own. If youwant to round it out into a full meal, it pairs perfectly with a simple green salad

FAQs

Can I make French onion soup ahead of time?

Yes! Make the soup base up to 3 days in advance and store it in the refrigerator. When you’re ready to serve, reheat the soup, ladle it into oven-safe bowls, top with bread and cheese, and broil as directed.

Do I have to use sherry and white wine?

You don’t. See the substitutions section above for easy swaps that still give the soup great flavor.

Why are my onions not caramelizing?

The two most common reasons are too much heat and not enough time. Medium heat and patience are the keys. If the onions are browning too fast or starting to stick, lower the heat and add a small splash of water. True caramelization takes at least 40 minutes.

Is it called “French onion soup” in France?

It is not! In France, this dish is “soupe a l’oignon,” which translates to plain onion soup. My husband and I learned this firsthand on a trip to Paris. We ordered it expecting the French onionsoup we knew and loved, and had a good laugh when we realized the name is entirely an American thing