Ingredients
Scale
- 4 large yellow onions, thinly sliced
- 3 tablespoons unsalted butter
- 2 tablespoons olive oil
- 4 cups beef broth (or vegetable broth for vegetarian)
- 1 teaspoon sugar
- 1 teaspoon salt
- 1/2 teaspoon black pepper
- 1/4 teaspoon thyme
- 1 baguette, sliced
- 2 cups grated Gruyere cheese
Instructions
- In a large pot, melt butter with olive oil over medium heat. Add sliced onions and cook slowly, stirring occasionally, until deeply caramelized (about 30-40 minutes).
- Add sugar, salt, pepper, and thyme, cooking for another 5 minutes.
- Pour in broth and bring to a simmer. Let simmer for 20 minutes to blend flavors.
- Meanwhile, preheat oven to 375°F (190°C). Toast baguette slices until golden brown.
- Ladle soup into oven-safe bowls, place toasted baguette on top, and sprinkle with grated Gruyere cheese.
- Broil in the oven until cheese is melted and bubbly, about 3-5 minutes. Serve hot with a spoon.
Notes
- Use a combination of yellow and sweet onions for maximum flavor.
- For vegetarian version, substitute beef broth with vegetable broth or mushroom broth.
- Ensure onions are caramelized slowly to develop rich sweetness.
- Prep Time: 10 minutes
- Cook Time: 50 minutes
- Method: Stovetop & oven
- Cuisine: French
- Diet: Comfort Food
Nutrition
- Serving Size: 1 bowl (approximately 350g)
- Calories: 320 Kcal
- Sugar: 8g
- Sodium: 850mg
- Fat: 15g
- Saturated Fat: 8g
- Unsaturated Fat: 6g
- Trans Fat: 0g
- Carbohydrates: 40g
- Fiber: 4g
- Protein: 14g
- Cholesterol: 50mg