Ingredients
Scale
- 4 large onions, thinly sliced
- 3 tablespoons unsalted butter
- 2 tablespoons olive oil
- 1 teaspoon sugar
- 4 cups beef broth (or vegetable broth for vegetarian option)
- 1/2 cup dry white wine (optional)
- 1 bay leaf
- 1 teaspoon fresh thyme leaves (or ½ teaspoon dried thyme)
- Salt and freshly ground black pepper to taste
- Baguette slices, toasted
- 1 ½ cups grated Gruyère cheese (or Swiss cheese)
Instructions
- Heat a large pot over medium heat and melt the butter with olive oil. Add the sliced onions and sugar. Cook slowly, stirring frequently, until onions turn a deep golden brown, about 30-40 minutes.
- Pour in white wine to deglaze the pan, scraping up browned bits. Add beef broth, bay leaf, and thyme. Season with salt and pepper. Bring to a boil, then reduce heat and simmer for 20-30 minutes.
- While simmering, toast baguette slices until golden. Preheat broiler. Ladle soup into oven-safe bowls, top with toasted baguette slices, and sprinkle generously with Gruyère cheese.
- Broil bowls for 2-3 minutes until cheese melts and becomes bubbly and golden. Carefully remove and serve immediately.
Notes
- Caramelize onions slowly on low heat for best flavor.
- Use hearty, crusty bread to ensure it holds up under cheese.
- Adjust seasonings; consider adding Worcestershire sauce or balsamic vinegar for extra depth.
- Prep Time: 10 minutes
- Cook Time: 40 minutes
- Category: Soup
- Method: Stovetop, Broiling
- Cuisine: French
- Diet: Vegetarian (if using vegetable broth)
Nutrition
- Serving Size: 1 bowl
- Calories: 310 kcal Kcal
- Sugar: 11 grams
- Sodium: 920 mg
- Fat: 15 grams
- Saturated Fat: 8 grams
- Unsaturated Fat: 7 grams
- Trans Fat: 0 grams
- Carbohydrates: 36 grams
- Fiber: 4 grams
- Protein: 12 grams
- Cholesterol: 45 mg