Ingredients
Scale
- 4 large sweet onions (Vidalia or yellow onions)
- 4 tablespoons unsalted butter
- 1 tablespoon olive oil
- 1 teaspoon sugar
- 4 cloves garlic, minced
- 8 cups beef or vegetable broth
- 1 cup dry white wine
- 2 teaspoons fresh thyme leaves
- Salt to taste
- Pepper to taste
- 1 baguette, sliced
- 2 cups shredded Gruyère cheese
Instructions
- Peel and thinly slice the onions.
- In a large skillet, melt butter and olive oil over medium heat. Add onions and sugar, cooking for 15-20 minutes until golden brown.
- Add minced garlic and cook for 1-2 minutes until fragrant.
- Transfer onions and garlic to a slow cooker, then add broth, wine, thyme, salt, and pepper.
- Cover and cook on low for 6-8 hours or on high for 3-4 hours.
- Preheat oven to 400°F (200°C). Toast baguette slices for 5-7 minutes until golden.
- Ladle soup into oven-safe bowls, top with toasted baguette, and sprinkle with Gruyère.
- Broil for 2-3 minutes until cheese is bubbly and golden. Serve hot.
Notes
- Use high-quality broth for the best flavor.
- You can substitute white wine with additional broth if needed.
- For extra depth, cook onions slower for deeper caramelization.
- Store leftovers in the refrigerator for up to 3 days.
- Prep Time: 20 minutes
- Cook Time: 6-8 hours (low) or 3-4 hours (high)
- Category: Soup
- Method: Slow Cooker
- Cuisine: French
- Diet: Low Lactose
Nutrition
- Serving Size: 1 bowl
- Calories: 320
- Sugar: 8g
- Sodium: 900mg
- Fat: 18g
- Saturated Fat: 9g
- Unsaturated Fat: 7g
- Trans Fat: 0g
- Carbohydrates: 25g
- Fiber: 3g
- Protein: 12g
- Cholesterol: 45mg