Description
This classic French Onion Soup, or Soupe à l’Oignon Gratinée, features deeply caramelized onions simmered in rich beef or chicken stock, enhanced with dry sherry and a touch of fish sauce and cider vinegar for depth. Topped with toasted rustic bread, garlic, and melted Gruyère cheese broiled to golden perfection, this soup is a comforting, flavorful dish perfect for cozy meals.
Ingredients
Soup Base
- 6 tablespoons (90g) unsalted butter, plus more for bread
- 3 pounds (1.4kg) yellow or mixed onions, sliced 1/8 inch thick
- Kosher salt and freshly ground black pepper to taste, divided
- 1/2 cup (120 ml) dry sherry (such as Amontillado)
- 2 quarts (1.8L) homemade beef stock or homemade or store-bought low-sodium chicken stock
- 2 sprigs thyme
- 1 bay leaf
- 1 teaspoon (5 ml) fish sauce (optional)
- 1 teaspoon (5 ml) cider vinegar
For Topping
- 8 bowl-size slices rustic bread, toasted until crisp
- 1 medium clove garlic
- 1 pound (450 g) Gruyère cheese, grated
- 2 tablespoons freshly minced chives, for garnish
Instructions
- Caramelize Onions: In a large stainless steel saucepan or two large stainless steel or cast iron skillets, melt butter over medium-high heat until it foams. Add the sliced onions and cook, stirring occasionally, until softened, about 8 minutes. Then lower the heat to medium-low and continue cooking the onions, stirring frequently, until they develop a rich golden-brown color and become very sweet, which should take 1 to 2 hours. If the browned onion juices on the bottom of the pan start to burn, add 1 tablespoon (15 ml) water, scrape up the browned bits, and continue cooking. Season the onions with salt and pepper to taste.
- Deglaze with Sherry: Add the dry sherry to the onions and bring to a simmer. Scrape up any browned bits stuck to the pan. If you used two skillets, divide the sherry between them and then transfer the onions and liquids into a single pot or Dutch oven to continue. Cook until the alcohol smell mostly dissipates, about 3 minutes.
- Add Stock and Herbs: Pour in the beef or chicken stock along with the thyme sprigs and bay leaf. Increase the heat to medium-high and bring the mixture to a simmer. Then reduce the heat to low and let it simmer gently for 20 minutes to allow the flavors to meld.
- Season the Soup: Stir in the fish sauce if using, and cider vinegar. Adjust seasoning with salt and pepper as needed. Remove and discard the thyme sprigs and bay leaf.
- Prepare Toasts: Preheat your oven broiler and adjust the rack to the top position. Butter the toasted rustic bread slices and rub each with the halved garlic clove until fragrant.
- Assemble Bowls: Spoon a small amount of broth into the bottom of 4 ovenproof serving bowls. Top each with half of the toasted bread slices, then sprinkle grated Gruyère cheese on top. Add more soup and onions to nearly fill the bowls. Place the remaining toasted bread slices on top, pushing them down to almost submerge, then cover with the remaining grated cheese.
- Broil Cheese Topping: Place the baking sheet with the filled bowls under the preheated broiler. Broil just until the cheese melts and turns golden with some browned spots, watching carefully to prevent burning.
- Garnish and Serve: Remove from the broiler and sprinkle freshly minced chives over each bowl. Serve the soup immediately while hot and bubbling.
Notes
- Using sliced onions about 1/8 inch thick ensures even caramelization.
- Fish sauce is optional but adds a subtle umami depth to the soup.
- Dry sherry enhances complexity; substitute with white wine if needed.
- Rustic bread like a baguette or country loaf works best for toasts.
- Gruyère cheese provides the classic nutty, melty topping.
- Keep a close watch while broiling to avoid burning the cheese.
- This soup is best served fresh but can be prepped to the point before broiling and refrigerated for up to 24 hours.
- Prep Time: 20 mins
- Cook Time: 2 hrs
- Category: Soup
- Method: Stovetop
- Cuisine: French
