French Onion Soup is a timeless dish that brings comfort to your table with its rich, deep flavors. This classic recipe showcases perfectly caramelized onions and a savory broth, topped with gooey, melted Gruyère cheese for the quintessential finish.

• Cuisine: French
• Prep Time: 20 minutes
• Cook Time: 1 hour 5 minutes
• Total Time: 1 hour 25 minutes
• Servings: 6

Why You’ll Love This Recipe

• Deep, complex flavors from caramelized onions and beef stock.
• Satisfying and warming, especially on cold days.
• Easy to prepare with common ingredients you probably have at home.
• Perfectly crusted cheese topping for an inviting and delicious finish.

Ingredients

• 3 lbs sweet onions, halved and thinly sliced: These build the soup’s sweet and savory base, essential for the classic flavor profile.
• 6 tablespoons unsalted butter: Used to caramelize the onions, providing a rich and buttery taste.
• 3 tablespoons all-purpose, unbleached flour: Aids in thickening the soup slightly and adds a nice nutty undertone.
• 1 cup red wine: Enhances the depth of flavor; can substitute with a dry white wine if preferred.
• 8 cups beef stock: Forms the soup’s broth and provides a robust meatiness.
• 2 bay leaves: Infuse the soup with a subtle herbal note.
• 4 sprigs fresh thyme: Aromatic and earthy, balancing the sweetness of the onions. Dried thyme can substitute (use 1 teaspoon).
• Salt and pepper to taste: Balances flavors; adjust to personal preference.
• 1 baguette, thinly sliced: Crisp base for the cheesy topping.
• 1 1/2 cups Gruyère cheese, grated: Melts deliciously over the soup, adding a creamy texture.

How to Make It

Step 1: Caramelize the Onions

In a large pot, melt the butter over medium heat. Add the sliced onions, stirring every few minutes. Cook until the onions are golden brown, soft, and caramelized—this takes about 30 minutes. Proper caramelization is essential for the soup’s depth; avoid high heat to prevent burning.

Step 2: Prepare the Base

Sprinkle the flour over the onions and cook, stirring continuously for about a minute until the flour is lightly browned. This step creates a roux that thickens the soup. Pour in the red wine, scraping the pot’s bottom to gather all the flavorful bits. Lower the heat and simmer until the wine reduces significantly.

Step 3: Simmer with Stock

Add the beef stock, bay leaves, and thyme sprigs to the pot. Bring to a boil, then reduce to a simmer. Cook uncovered for 30 more minutes until the liquid reduces. This reduction concentrates the flavors. Discard the bay leaves and thyme, and season with salt and pepper.

Step 4: Prepare the Baguette

While the soup simmers, preheat the broiler. Place the thin baguette slices on a baking sheet. Brush the tops lightly with olive oil and broil until toasted, about 2-3 minutes. These become the crunchy base for the cheese topping.

Step 5: Assemble and Broil

Ladle the soup into oven-safe bowls, top each with toasted baguette slices, and generous amounts of Gruyère cheese. Place under the broiler for 2-3 minutes until the cheese is bubbly and golden. This step adds the perfect cheesy layer to your soup.

Recipe FAQs

Can I make this soup vegetarian?

Yes, substitute the beef stock with vegetable stock. The flavor profile will change slightly, but it will still be deliciously savory.

What can I use instead of Gruyère cheese?

If Gruyère is unavailable, Swiss cheese or Emmental are great alternatives, offering a similar melt and flavor.

How can I store leftovers?

Allow the soup to cool, then store it in an airtight container in the refrigerator for up to 3 days. Reheat gently on the stove, and toast fresh baguette slices when ready to serve again.