Save When the temperature drops, few dishes offer as much solace as a bowl of Caramelized French Onion Soup. This recipe is a celebration of patience and simple ingredients, transforming humble yellow onions into a rich, mahogany-hued masterpiece. Topped with tangy sourdough and a thick layer of melted Gruyere, it is the ultimate winter comfort dish that brings the warmth of a French bistro right into your home.
Save The key to this soup's incredible depth is the caramelization. By slowly cooking the onions for nearly 45 minutes, you unlock layers of flavor that cannot be rushed. Deglazing the pot with dry white wine ensures that every savory bit of 'fond'—the browned bits at the bottom—is incorporated into the broth, resulting in a complex and satisfying finish.
Ingredients
- For the Soup:
- 6 large yellow onions, thinly sliced
- 3 tbsp unsalted butter
- 1 tbsp olive oil
- 1 tsp sugar
- 1 tsp salt
- 1/2 tsp freshly ground black pepper
- 2 cloves garlic, minced
- 2 tbsp all-purpose flour
- 1/2 cup dry white wine
- 6 cups beef broth (or vegetable broth for vegetarian)
- 2 sprigs fresh thyme (or 1/2 tsp dried)
- 1 bay leaf
- Salt and pepper, to taste
- For the Sourdough Gruyere Crostini:
- 1 small sourdough baguette, sliced into 1/2-inch rounds
- 2 tbsp olive oil
- 1 cup Gruyere cheese, grated
- 1/2 cup Parmesan cheese, grated (optional)
Instructions
- 1. Caramelize the Onions
- In a large heavy-bottomed pot, melt butter and olive oil over medium heat. Add sliced onions, sugar, salt, and pepper. Cook, stirring frequently, for 35–45 minutes until onions are deep golden and caramelized.
- 2. Add Aromatics
- Stir in the garlic and cook for 1 minute.
- 3. Prepare the Roux
- Sprinkle flour over onions; cook, stirring, for 2 minutes to remove the raw flour taste.
- 4. Deglaze the Pot
- Pour in white wine, scraping up any browned bits from the bottom. Simmer for 2–3 minutes to reduce.
- 5. Simmer the Soup
- Add beef broth, thyme, and bay leaf. Bring to a gentle boil, then reduce heat and simmer uncovered for 25–30 minutes. Adjust seasoning with salt and pepper. Discard thyme sprigs and bay leaf.
- 6. Toast the Sourdough
- While soup simmers, preheat oven to 400°F (200°C). Arrange baguette slices on a baking sheet, brush with olive oil, and toast for 5–7 minutes until golden.
- 7. Melt the Cheese
- Top toasts with Gruyere (and Parmesan, if using). Return to oven and bake until cheese is melted and bubbly, about 3–4 minutes.
- 8. Assemble and Serve
- Ladle soup into oven-safe bowls, place crostini on top, and broil for 1–2 minutes if extra melt is desired. Serve hot.
Zusatztipps für die Zubereitung
For an extra layer of richness, consider adding a splash of brandy or sherry to the soup just before serving. It is also important to double-check labels for broths and cheeses if you are sensitive to allergens like gluten or sulfites found in wine.
Varianten und Anpassungen
To make this soup vegetarian, simply substitute the beef broth with a high-quality vegetable broth and ensure the Parmesan cheese is vegetarian-friendly. If Gruyere is unavailable, Emmental or Swiss cheese make excellent substitutes that melt beautifully.
Serviervorschläge
This soup pairs exquisitely with a crisp white wine such as Sauvignon Blanc, which cuts through the richness of the caramelized onions and cheese. For the best presentation, use individual oven-safe crocks that allow the cheese to bubble over the edges during the final broil.
Save Whether you are hosting a formal dinner or simply looking for a way to warm up on a snowy afternoon, this Caramelized French Onion Soup is sure to satisfy. Serve it piping hot and enjoy the perfect balance of savory broth, sweet onions, and molten cheese.
Recipe Questions
- → How do you achieve deep caramelization of onions?
Cook thinly sliced onions slowly over medium heat with butter and olive oil, stirring frequently for 35–45 minutes until they turn deep golden brown and sweet.
- → Can vegetable broth replace beef broth without losing flavor?
Yes, using vegetable broth offers a lighter, vegetarian-friendly base while still complementing the caramelized onions and herbs well.
- → What is the best cheese for the crostini topping?
Gruyere provides a rich, nutty flavor that melts beautifully, creating a golden, bubbly topping. Parmesan adds extra sharpness if desired.
- → How is the sourdough prepared for the crostini?
Sourdough baguette slices are brushed with olive oil, toasted until golden, then topped with cheese and baked again until melted and bubbly.
- → Can this dish be made ahead of time?
The soup and crostini can be prepared in advance; reheat the soup gently and bake the crostini fresh to maintain crispiness before serving.