Description
This classic French Onion Soup recipe features deeply caramelized onions simmered in a rich beef and chicken broth, enhanced with white wine and aromatic herbs. Topped with toasted baguette slices smothered in melted Gruyere cheese, this comforting and savory soup is perfect for a cozy meal.
Ingredients
Onions
- 4 large yellow onions (about 3 pounds)
- 2 large sweet onions (Vidalia)
Cooking Fats and Liquids
- 6 Tablespoons butter
- ¾ cup dry white wine (Chardonnay or Pinot Grigio)
- 4 cups beef broth (high quality)
- 1.5 cups chicken broth
- 3 Tablespoons olive oil (optional, for toasting baguette)
Thickener and Seasonings
- 2 sprigs fresh thyme
- 2 Bay leaves
- 3 tablespoons flour (optional)
- 1 beef bouillon cube (or 1 tsp Better Than Bouillon)
- 1 teaspoon Worcestershire sauce
- Salt and pepper (to taste)
Bread and Cheese
- 1 baguette
- 6 slices Gruyere cheese
Instructions
- Slice the onions: Cut the yellow and sweet onions into ¼-inch thick slices. Keeping the slices uniform and not too thin ensures they caramelize properly and don’t become stringy. Using a mandoline slicer helps achieve consistent thickness.
- Melt the butter: Place butter in a large soup pot or Dutch oven over medium-low heat. Allow it to melt fully and begin to foam. This foaming step helps evaporate water from the butter, making it more clarified and smooth for better caramelization.
- Add and coat onions: Add the sliced onions to the melted butter. Use tongs to toss and coat the onions evenly. Leave the pot uncovered to allow moisture to escape as onions cook.
- Caramelize onions: Cook the onions slowly over medium-low heat for up to 2 hours or longer, stirring every 10-15 minutes. The onions will soften and develop a rich deep brown color. If brown bits stick to the pot, add a splash of white wine and use a silicone spatula to scrape and deglaze the pot surface. Repeat this process throughout cooking as needed.
- Add flour and wine: When onions are nearly fully caramelized, sprinkle flour evenly over them and cook for 2 minutes to cook out the raw flour taste. Add any remaining white wine, increase heat to medium-high, and toss onions frequently until they are richly brown and sweet.
- Add liquids and herbs: Stir in beef broth, beef bouillon cube (or bouillon paste), chicken broth, Worcestershire sauce, bay leaves, and fresh thyme sprigs. Bring to a simmer over medium heat, partially cover with a lid cracked open, and simmer gently for 45 minutes to meld flavors.
- Preheat oven: While soup simmers, preheat your oven to 350°F (175°C) for toasting the bread.
- Toast baguette slices: Slice the baguette into ½-inch thick rounds. Brush the tops lightly with olive oil, then bake them in the oven for about 5 minutes until lightly toasted but not browned.
- Melt the cheese: Increase oven temperature to 450°F (230°C). Place Gruyere cheese slices atop each baguette round and return to oven. Bake until the cheese melts, bubbles, and starts to brown—about 3-5 minutes.
- Finalize soup seasoning: Remove bay leaves and thyme stems from the soup. Taste and adjust seasoning with salt and pepper as desired.
- Serve: Ladle warm soup into bowls and top each with a cheesy baguette slice. Serve immediately for a comforting, hearty meal.
Notes
- Use high-quality beef broth for best flavor depth in the soup.
- Slow caramelization of onions is key to developing the soup's signature rich sweetness – don’t rush this step.
- The flour is optional but helps slightly thicken the soup for a better texture.
- Gruyere cheese melts well and adds a wonderful nutty taste, but Swiss cheese is a common substitute.
- Using a mandoline slicer for onion slicing saves time and ensures uniform slices.
- The white wine deglazes the pot and adds acidity to balance the sweetness of the onions.
- Prep Time: 20 minutes
- Cook Time: 2 hours 35 minutes
- Category: Soup
- Method: Stovetop
- Cuisine: French
