Description
This classic French Onion Soup recipe features deeply caramelized onions simmered in a savory broth, topped with toasted baguette slices and melted Gruyere cheese. Rich, flavorful, and perfect for cozy dining, this comforting soup blends sweet onions and wine with hearty beef and chicken broth, finished in the oven for a golden cheesy crust.
Ingredients
Scale
Onions
- 4 large yellow onions (about 5 pounds total)
- 2 large sweet Vidalia onions
Cooking Base
- 6 Tablespoons butter
- 2 sprigs fresh thyme
- 2 Bay leaves
- ¾ cup dry white wine (Chardonnay or Pinot Grigio)
- 3 tablespoons flour (optional)
- 4 cups beef broth (high quality)
- 1 beef bouillon cube or 1 tsp Better Than Bouillon
- 1.5 cups chicken broth
- 1 teaspoon Worcestershire sauce
- Salt and Pepper to taste
For the Topping
- 1 baguette
- 3 Tablespoons olive oil (optional)
- 6 slices Gruyere cheese
Instructions
- Slice Onions: Slice the onions into ¼-inch thick slices using a mandoline slicer if available. This thickness ensures the onions caramelize evenly without becoming too stringy.
- Melt Butter and Start Cooking Onions: In a large soup pot or Dutch oven, melt butter over medium-low heat until it begins to foam, which clarifies the butter. Add the sliced onions and toss to coat using tongs. Leave the pot uncovered as the onions slowly cook.
- Caramelize Onions: Allow the onions to caramelize slowly over medium-low heat for up to 2 hours, stirring every 10-15 minutes to prevent sticking and burning. Use a splash of white wine to deglaze the bottom of the pot whenever brown residue forms.
- Add Flour and Wine: When onions are nearly fully caramelized and richly brown, sprinkle flour over them if using, and cook for 2 minutes. Add any remaining wine, increase heat to medium-high, and toss frequently until the onions are deeply brown and sweet.
- Add Broth and Simmer: Stir in beef broth, beef bouillon, chicken broth, Worcestershire sauce, bay leaves, and thyme. Simmer the soup over medium heat with the lid cracked for 45 minutes to meld flavors.
- Prepare Baguette Slices: While the soup simmers, preheat oven to 350°F (175°C). Slice the baguette into ½-inch thick slices. Brush the tops with olive oil if desired and bake for about 5 minutes until slightly toasted.
- Melt Cheese on Toasted Baguette: Increase oven temperature to 450°F (230°C). Top each toasted baguette slice with Gruyere cheese and bake until the cheese melts, bubbles, and begins to brown lightly.
- Finish Soup: Remove bay leaves and thyme stems from the soup. Season with salt and pepper to taste. Ladle soup into bowls and top each with a warm, cheesy baguette slice. Serve immediately.
Notes
- Use about 5 pounds of onions total for the best flavor and texture.
- If you prefer no wine, substitute 3 Tablespoons white wine vinegar plus chicken or beef broth to make ¾ cup liquid.
- Alternative cheeses that melt well include Comte, Emmental (Swiss), or Provolone.
- Crock Pot Method: Melt 4 Tablespoons butter in the crock pot, add onions and toss. Cook on low for 10 hours for slow caramelization. Then use stovetop to finish with butter, flour, wine, and simmer broth mixture as described.
- Be sure to deglaze the pot often during caramelization to prevent burning and add flavor.
- The slow, low heat caramelization is key to the soup’s deep rich flavor.
Nutrition
- Serving Size: 1 bowl with baguette and cheese topping
- Calories: 320
- Sugar: 9g
- Sodium: 850mg
- Fat: 20g
- Saturated Fat: 12g
- Unsaturated Fat: 6g
- Trans Fat: 0g
- Carbohydrates: 26g
- Fiber: 3g
- Protein: 12g
- Cholesterol: 40mg
