This recipe uses all the classic techniques and ingredients for a truly unforgettable bowl of French Onion Soup with Gruyere.
Let me be honest about French onion soup: it’s not a hurry-up soup. You can’t rush caramelized onions, and trust me, I’ve tried. I’ve cranked the heat, gotten impatient, and ended up with onions that were somehow both scorched and raw. The soup gods were not amused.
But when you give the onions the time they deserve, something magical happens. Five pounds of onions cook down into a sweet, jammy, mahogany pile that tastes like it took all day, because it sort of did. Add a rich beef broth, a splash of Worcestershire, and a toasted baguette buried under bubbling Gruyère, and you have the coziest bowl of soup I know.
Why This French Onion Soup Recipe Works
Low and slow onions build the flavor. Cooking sweet onions in butter over medium-low heat for 45 minutes brings out their natural sugars, which gives the soup its deep, sweet, savory base.
Beef consommé is my secret shortcut. A couple of cans of Campbell’s beef consommé add a concentrated, restaurant-style richness that broth alone can’t match. It’s a little bit of a cheat, and I’m completely at peace with that.
Worcestershire adds depth. Just two teaspoons give the soup a savory, umami backbone.
Toasting the bread first keeps it from getting soggy. A quick bake means the baguette holds up under the cheese instead of dissolving into the soup.
French Onion Soup
Serves 4 to 6 | Prep: 20 minutes | Cook: 1 hour 45 minutes | Total: about 2 hours
Ingredients
- 6 large sweet onions (about 5 lbs. total)
- 8 Tbsp. (1 stick) unsalted butter
- 3 sprigs fresh thyme
- 2 bay leaves
- 5 cups beef broth (chicken broth works in a pinch)
- 2 (10.5-oz.) cans Campbell’s beef consommé
- 2 tsp. Worcestershire sauce
- 1 tsp. salt, plus more to taste
- 1 tsp. freshly cracked black pepper
- 1 baguette
- 3 Tbsp. olive oil (optional)
- ¼ cup shredded Gruyère cheese per bowl (1 to 1½ cups total)
Instructions
- Slice the onions. Halve the onions and slice them into ¼-inch-thick slices.
- Start the onions. Melt the butter in a large soup pot or Dutch oven over medium-low heat. When it begins to foam, add the onions and toss to coat them in butter.
- Caramelize low and slow. Cook the onions, stirring every 10 to 15 minutes, until they are deeply browned, soft, and sweet, about 45 minutes. If they start sticking or browning too fast, lower the heat and add a splash of water.
- Simmer the soup. Add the beef broth, beef consommé, Worcestershire sauce, bay leaves, and thyme sprigs. Bring to a gentle simmer and cook for 45 minutes.
- Toast the bread. While the soup simmers, preheat the oven to 350°F. Slice the baguette into ½-inch-thick slices, brush the tops with olive oil if using, and bake on a baking sheet until lightly toasted, about 5 minutes.
- Season. Increase the oven temperature to 450°F. Remove the bay leaves and thyme stems from the soup, then season with salt and pepper to taste.
- Assemble. Set oven-safe bowls on a rimmed baking sheet. Ladle the hot soup into the bowls and top each with 1 or 2 toasted baguette slices and about ¼ cup Gruyère.
- Broil the cheese. Bake until the cheese is melted, bubbling, and starting to brown, 5 to 8 minutes. Carefully remove the baking sheet (the bowls will be very hot) and serve.
Tips for the Best French Onion Soup
Use sweet onions. Vidalia or other sweet onions caramelize beautifully and give the soup a mellow sweetness. Yellow onions work too, with a slightly sharper flavor.
Don’t crowd the heat. If your onions are browning in spots before they’ve softened, turn the heat down. Patience is the whole recipe.
Use oven-safe bowls and a baking sheet. The baking sheet catches drips and makes it much easier (and safer) to move hot bowls in and out of the oven.
Be generous with the cheese. A quarter cup per bowl is my baseline, but nobody has ever complained about extra Gruyère. For a sharper flavor, mix in a little Swiss or Parmesan.
Make it ahead. The soup base is even better the next day. Refrigerate it, then reheat and do the bread and cheese right before serving.
No oven-safe bowls? Toast the baguette slices, top them with cheese, and broil them on a baking sheet until bubbly. Then float them on top of the soup.
French Onion Soup FAQ
How long does it take to caramelize onions for French onion soup?
About 45 minutes over medium-low heat. The onions should be deeply golden brown, soft, and sweet. Rushing them over high heat makes them burn instead of caramelize.
What are the best onions for French onion soup?
Sweet onions such as Vidalia give the soup a rich, mellow sweetness. Yellow onions are a classic choice and give a slightly more robust flavor.
What cheese goes on French onion soup?
Gruyère is traditional because it melts smoothly and has a nutty, savory flavor. Swiss, Emmental, or a blend with Parmesan also work well.
Can I use chicken broth instead of beef broth?
Yes. Chicken broth makes a lighter soup, and the beef consommé still gives it plenty of rich, beefy flavor.
Can I make French onion soup ahead of time?
Yes. Make the soup base up to 4 days ahead and store it in the refrigerator. Reheat it on the stove and add the toasted bread and cheese just before serving.
Can I freeze French onion soup?
Yes. Freeze the soup base without the bread and cheese for up to 3 months. Thaw it overnight in the refrigerator before reheating.
Love Soup? Try these other recipes:
French Onion Soup Recipe
Equipment
Ingredients
- 6 large sweet onions about 5 lbs total
- 8 Tbsp unsalted butter
- 3 sprigs fresh thyme
- 2 Bay leaves
- 5 cups beef broth I often substitute chicken broth if that’s all I have
- 2 cans Campbell’s soup beef consommé
- 2 teaspoons Worcestershire sauce
- 1 teaspoon salt
- 1 teaspoon cracked fresh pepper
- 1 baguette
- 3 Tbsp olive oil
- ¼ cup Gruyère cheese for each bowl of soup
Instructions
- Slice the onions into ¼ inch thick slices
- Melt the butter in a large soup pot or Dutch Oven over medium-low heat.
- When it begins to foam add the onions and toss to coat them in the butter.
- The onions will cook and caramelize slowly (about 45 minutes)
- Stir the onions every 15 minutes.
- They are done when they are richly brown and sweet (about 45 minutes)
- Add the beef broth, chicken broth, Worcestershire sauce, bay leaves, and thyme. Simmer for another 45 minutes.
- While the soup simmers, preheat the oven to 350 degrees.
- Slice the baguette into ½-inch-thick slices.
- Brush the tops of the baguettes with olive oil and bake for about 5 minutes to toast
- Increase the oven temperature to 450 degrees.
- Remove the bay leaves and thyme stems. Season to taste with salt and pepper.
- Ladle the warm soup into the bowls
- Top each bowl with 1 or 2 baguette slices, add Gruyère cheese, and bake in the oven until the cheese melts and begins to bubble and brown.
