Description
This Slow Cooker French Onion Soup is rich, savory, and perfect for cozy nights. Caramelized onions, simmered in beef broth with herbs, are finished with toasted baguette slices and gooey melted cheese for the ultimate comfort food.
Ingredients
Scale
- 5 large yellow onions, thinly sliced
- 3 tbsp unsalted butter
- 1 tbsp olive oil
- 3 cloves garlic, minced
- 1 tsp sugar
- 1 tsp salt
- 1/2 tsp black pepper
- 2 tbsp all-purpose flour
- 8 cups beef broth
- 1/2 cup dry white wine (optional)
- 2 sprigs fresh thyme (or 1 tsp dried thyme)
- 1 bay leaf
- 1 baguette, sliced and toasted
- 2 cups shredded Gruyère or Swiss cheese
Instructions
- In a skillet, melt butter with olive oil over medium heat. Add onions, sugar, salt, and pepper. Cook until golden and caramelized, about 20–25 minutes.
- Transfer onions to a slow cooker. Stir in garlic and flour until combined.
- Add beef broth, wine (if using), thyme, and bay leaf. Cover and cook on LOW for 6–8 hours or HIGH for 3–4 hours.
- Remove thyme sprigs and bay leaf. Preheat oven broiler.
- Ladle soup into oven-safe bowls, top with toasted baguette slices, and sprinkle generously with Gruyère cheese.
- Broil until cheese is melted and bubbly, about 2–3 minutes. Serve hot.
Notes
For vegetarian variation, substitute beef broth with rich vegetable broth and use vegetarian-friendly cheese.
- Prep Time: 20 minutes
- Cook Time: 6 hours
- Category: Soup
- Method: Slow Cooker
- Cuisine: French-American
Nutrition
- Serving Size: 1 bowl
- Calories: 320
- Sugar: 9g
- Sodium: 880mg
- Fat: 14g
- Saturated Fat: 8g
- Unsaturated Fat: 6g
- Trans Fat: 0g
- Carbohydrates: 31g
- Fiber: 3g
- Protein: 13g
- Cholesterol: 40mg
Keywords: slow cooker french onion soup, crockpot onion soup, easy french onion soup, comfort food soup recipe