Ingredients
Scale
- 4 large yellow onions, thinly sliced
- 3 tablespoons unsalted butter
- 2 tablespoons olive oil
- 4 cups beef broth
- 1 cup dry white wine (optional)
- 2 teaspoons sugar
- 1 teaspoon salt
- 1/2 teaspoon black pepper
- 1 teaspoon fresh thyme or 1/2 teaspoon dried thyme
- Baguette slices, toasted
- 2 cups grated Gruyere cheese
Instructions
- Heat butter and olive oil in a large pot over medium heat. Add sliced onions and cook, stirring frequently, until caramelized and golden brown, about 30-40 minutes.
- Add sugar, salt, pepper, and thyme to the onions. Stir well and cook for another minute.
- Pour in the white wine (if using) and cook until reduced by half, about 5 minutes.
- Add beef broth and bring the mixture to a simmer. Let simmer for 15-20 minutes to develop flavor.
- Preheat the oven broiler. Ladle the hot soup into oven-safe bowls. Top each with toasted baguette slices and sprinkle generously with grated Gruyere cheese.
- Place the bowls on a baking sheet and broil until the cheese is bubbly and golden, about 3-5 minutes.
Notes
- Caramelizing onions slowly yields the deepest flavor; patience is key.
- You can substitute beef broth with vegetable broth for a vegetarian version.
- Use fresh thyme for the best aroma and taste.
- Prep Time: 10 minutes
- Cook Time: 50 minutes
- Method: Sauté, simmer, broil
- Cuisine: French
- Diet: Comfort food
Nutrition
- Serving Size: 1 bowl
- Calories: 340 Kcal
- Sugar: 8g
- Sodium: 950mg
- Fat: 15g
- Saturated Fat: 9g
- Unsaturated Fat: 4g
- Trans Fat: 0g
- Carbohydrates: 40g
- Fiber: 4g
- Protein: 15g
- Cholesterol: 50mg