French Onion Soup Recipe

The Best French Onion Soup Recipe

We love going to our neighborhood restaurant for French onion soup, but it’s far from light. I wanted to recreate their soup at home so I could enjoy it more often but with fewer calories. This French onion soup is easy to make and lighter than most restaurant versions. A hearty bowl is the perfect meal this time of year when it’s so cold outside. I don’t know about you, but for me, I’ve got all my favorite cozy soup recipes on frequent rotation in the winter!

What You’ll Need

Scroll down to the recipe card below for exact measurements.

• Yellow onions – I use yellow onions in my French onion soup, but you could use Vidalia, white, or red onions.
• Unsalted butter –  You can substitute olive oil if you prefer, but I like the richness that butter adds.
• Flour – This helps thicken the soup a bit.
• Herbs – Bay leaf and dried thyme both add flavor to this soup.
• Dry sherry –  If you don’t cook with alcohol, you can use extra broth instead (for this and the next 2 ingredients as well), but I’d suggest adding a splash of balsamic vinegar or sherry vinegar for some depth.
• Cognac or brandy – Cognac is my favorite addition to French onion soup, but brandy works too.
• White wine – Sauvignon Blanc, Pinot Grigio, or another dry white wine.
• Beef broth – You can use store-bought or homemade.
• Salt and pepper – I use kosher salt and freshly ground black pepper.
• Bread – I like to use toasted Italian bread.
• Reduced-fat Swiss – Like Alpine Lace.

How to Make French Onion Soup

While it does take a bit of time to caramelize the onions, this recipe is very easy. See the recipe card below for printable instructions.

1. Caramelize the onions. Cook the onions with the butter in a large pot until they’re caramelized—this will take 20 to 30 minutes. If needed, add a splash of water to keep them from getting dry.
2. Add the next few ingredients. Stir in the flour for 2 to 3 minutes, then add the herbs, sherry, wine, and brandy. Simmer uncovered for 10 minutes.
3. Continue to simmer. Pour in the beef broth and season with salt and pepper. Reduce the heat, cover, and simmer for 20 minutes. 
4. Divide into bowls. Remove the bay leaf and ladle the soup into oven-proof bowls set on a baking sheet. Place toasted bread slices into the soup, then top with cheese.
5. Broil. Place the baking sheet in the oven and broil for 2 to 3 minutes, or until the cheese melts. Keep an eye on it—the cheese can burn quickly if left under the broiler for too long.

Tips and Variations

Here are some tips and variations I’ve come up with over the years of making this French onion soup.

• Use a good beef stock. I usually make my own beef stock, which makes all the difference in the flavor but canned works fine too, as long as you use one you really like. This Best Beef Broth and Stock article from Epicurious is really helpful. I’ve also done this with half beef and half chicken broth.
• Make it low carb. You can make this soup low carb by swapping out the bread for steamed cauliflower to hold the cheese up. Another low-carb trick I like to use is making Parmesan crisps (without the everything bagel seasoning) and using that top hold the cheese when melting.
• Make it gluten-free. Make the soup gluten-free by subbing in gluten-free flour and bread.
• Swap out the cheese. Use Gruyere or another white cheese, such as fontina, mozzarella or provolone, instead of the reduced-fat Swiss if you prefer.
• Meal prep it. The broth can be made ahead and refrigerated for up to 4 days. Reheat on the stove, then toast the bread and melt the cheese before serving.

Serving Suggestions

French onion soup is great by itself, but you could serve it with a salad to round out your meal. Try the soup with my berry salad with goat cheese or arugula salad with fig and prosciutto. You could also serve the soup as a starter for any meal. It would be perfect paired with roast beef and roasted brussels sprouts.

Proper Storage

• Refrigerator: Store French onion soup in an airtight container for up to 4 days.
• Freezer: You can freeze the soup without the cheese and bread for up to 3 months. Thaw in the refrigerator before reheating.
• To reheat: Place the soup in a pot and warm it up over medium heat until it starts to simmer. Simmer for a few minutes, then divide it into bowls, add the bread and cheese, and broil as directed.

More Soup Recipes You’ll Love

• Classic Potato Leek Soup
• Kale and Potato Soup with Turkey Sausage
• Chicken Noodle Soup
• Cream of Asparagus Soup
• Golden Red Lentil Soup with Spinach