Description
This French onion soup delivers a deeply savory, sweet onion broth topped with toasted bread and a blanket of bubbling Gruyère. It’s a classic bistro dish made approachable with Alton Brown’s precise method, and it’s completely alcohol-free and pork-free for everyone to enjoy. The result is a rich, comforting bowl with a golden, cheesy crust that crackles under the spoon.
Ingredients
- 2 tablespoons unsalted butter
- 2 tablespoons olive oil
- 3 pounds yellow onions, about 6 medium, thinly sliced
- 1 teaspoon kosher salt
- 1/2 teaspoon freshly ground black pepper
- 1 teaspoon granulated sugar
- 2 tablespoons all-purpose flour
- 8 cups low-sodium beef broth
- 2 cups water
- 2 sprigs fresh thyme
- 1 bay leaf
- 1 tablespoon balsamic vinegar
- 1 teaspoon Worcestershire sauce (anchovy-based, pork-free)
- 4 slices French baguette, cut 3/4-inch thick
- 8 ounces Gruyère cheese, grated (about 2 cups)
Instructions
- Preheat the oven to 450°F (230°C). Arrange the baguette slices on a baking sheet and toast in the oven until dry and lightly golden, about 6-8 minutes. Remove and set aside; leave the oven on for the final broil.
- In a large Dutch oven or heavy-bottomed pot, melt the butter with the olive oil over medium heat. Add the sliced onions, kosher salt, and black pepper. Cook, stirring occasionally, until the onions have softened and released their liquid, about 10 minutes.
- Reduce the heat to medium-low and add the sugar. Continue cooking, stirring every few minutes and scraping up the browned bits, until the onions are deeply caramelized and jammy, 60-75 minutes. If the onions start to stick or burn, add a tablespoon of water and scrape the bottom.
- Sprinkle the flour over the caramelized onions and cook, stirring constantly, for 1-2 minutes to remove the raw flour taste. The mixture will look dry and pasty.
- Slowly pour in 1 cup of the beef broth while stirring to create a smooth paste. Then add the remaining broth, water, thyme sprigs, and bay leaf. Increase the heat to medium-high and bring to a simmer.
- Reduce the heat to low and simmer uncovered for 20 minutes to meld the flavors. Stir in the balsamic vinegar and Worcestershire sauce, then taste and adjust seasoning with additional salt and pepper if needed. Remove the thyme sprigs and bay leaf.
- While the soup simmers, preheat the broiler to high and position an oven rack 6 inches from the heat source. Place four oven-safe crocks or bowls on a baking sheet.
- Ladle the hot soup into the crocks, filling them about three-quarters full. Place one toasted baguette slice on top of each, then divide the grated Gruyère evenly over the bread.
- Broil until the cheese is melted, bubbling, and golden brown in spots, 3-5 minutes. Watch carefully to prevent burning. Carefully remove the baking sheet from the oven and let the soup rest for 2 minutes before serving.
Notes
Storage: Cool leftover soup completely, then transfer to airtight containers. Refrigerate for up to 4 days or freeze for up to 3 months. To reheat, thaw overnight in the refrigerator if frozen, then warm gently in a saucepan over low heat until hot, about 10 minutes. For the best texture, toast fresh bread and melt cheese under the broiler just before serving; avoid reheating the cheese-topped soup in the microwave as the bread will become soggy. If you prefer a vegetarian version, substitute vegetable broth and omit the Worcestershire sauce. For a deeper flavor, use homemade beef broth.
Nutrition
- Calories: 620
- Sugar: 14g
- Sodium: 1320mg
- Unsaturated Fat: 16g
- Carbohydrates: 42g
- Fiber: 5g
- Protein: 32g
- Cholesterol: 80mg
Keywords: french onion soup, alton brown, onion soup recipe, gruyere cheese, beef broth, non-alcoholic, pork-free, comfort food, classic bistro, caramelized onions, winter soup, easy french onion