This French Onion Soup is rich, cozy, and downright irresistible—the kind of dish that warms you from the inside out. With deeply caramelized onions, savory broth, golden homemade croutons, and a gooey, bubbling cheese topping, every spoonful is packed with comforting flavor. It’s simple enough for a weeknight but fancy enough to impress guests. This recipe was adapted from the delicious version at Jillian Harris, and it’s absolutely worth making—just be prepared for everyone to ask for seconds!
Ingredients:
- 2 Tbsp. olive oil
- 1 Tbsp. butter
- 3 large yellow onions, thinly sliced
- 6 cloves garlic, crushed
- 5 cups prepared beef broth
- Salt and pepper, to taste
- Croutons (see recipe below)
- 1 ½ cups grated or sliced Gruyère, mozzarella, or Swiss cheese
- ½ loaf day-old bread, cut into cubes
- Parmesan cheese, for topping
- Chopped parsley, for garnish
Instructions:
Prepare the Croutons:
- Preheat the oven to 210°F (100°C).
- Slice and cube the day-old bread. Spread the cubes evenly on a wire cooling rack placed over a baking sheet to allow for proper air circulation.
- Bake for 45 minutes, or until the croutons are dry and crisp, tossing them halfway through for even browning. Remove from the oven and set aside.
Prepare the Soup:
- In a large, heavy-bottomed pot, heat the olive oil and butter over medium-low heat. Add the sliced onions and crushed garlic, stirring occasionally until softened and fragrant, about 10 minutes.
- Reduce the heat to low and continue cooking for about 30 minutes, stirring occasionally, until the onions become deeply golden brown and caramelized.
- Pour in the beef broth, scraping the bottom of the pot to incorporate any caramelized bits. Season with salt and pepper to taste, then let the soup simmer for an additional 10–15 minutes to allow the flavors to develop.
- Preheat the oven to broil.
- Arrange four oven-safe soup bowls on a baking sheet. Ladle the hot soup into each bowl, then top with a generous handful of croutons and a layer of grated or sliced cheese.
- Place under the broiler for 3–5 minutes, or until the cheese is melted, bubbling, and golden brown. Keep a close watch to prevent burning.
- Remove from the oven and immediately sprinkle with freshly grated Parmesan and chopped parsley for garnish.
- Serve hot and enjoy—pair with a light green salad or crusty bread for a complete meal.
Notes:
- For a deeper flavor, consider deglazing the onions with ¼ cup of dry white wine before adding the broth. Let the wine cook off for 2–3 minutes before proceeding.
- If a thicker consistency is preferred, allow the soup to simmer for a longer period to reduce slightly.
- Storage: Leftover soup (without toppings) can be refrigerated in an airtight container for up to 3 days. Reheat over low heat on the stovetop before serving.
Cooking French onion soup on the stove is a slow and satisfying process that builds deep, rich flavor from simple ingredients. It all starts with patiently caramelizing thinly sliced onions in butter or oil over low to medium heat. This step can take 30–40 minutes but is key to developing the soup’s signature sweetness and depth. Stirring often ensures the onions don’t burn but instead turn a soft, golden brown. A splash of white wine, sherry, or brandy can be added to deglaze the pot, lifting up all the browned bits for even more flavor.
Once the onions are perfectly caramelized, beef broth (or vegetable broth for a lighter version) is added, and the soup is left to simmer gently on the stove. This slow simmer helps meld the flavors, creating a savory, comforting broth. A touch of thyme or bay leaf can be added for aroma. When ready to serve, the hot soup is ladled into oven-safe bowls, topped with toasted bread and cheese, and then broiled until the top is golden and bubbling. But it all begins on the stove—where humble onions are transformed into a French classic.
To assemble your bowl of French onion soup before baking, start by ladling the hot soup into an oven-safe bowl, filling it about three-quarters full. Place a slice of toasted baguette or crusty sourdough on top, letting it rest slightly submerged. Then add your cheese—either lay a slice of Gruyère, Swiss, or mozzarella directly over the bread for a classic melt, or sprinkle a generous amount of grated cheese for a bubbly, golden finish. Set the bowl on a baking sheet to catch any drips, and it’s ready to go under the broiler or into the oven until the cheese is melted and lightly browned.
For an extra layer of flavor, consider sprinkling freshly grated Parmesan on top—either just before broiling to create a rich, golden crust, or right after broiling for a finishing touch of sharp, nutty flavor. To brighten the presentation, add a small sprig of fresh parsley or another green herb like thyme or chives as a garnish. It adds a pop of color and a subtle freshness that balances the deep, savory richness of the soup.
