Description
This Slow Cooker French Onion Soup is a comforting and flavorful classic made easy with caramelized onions, rich beef and chicken broth, and aromatic herbs. Finished with toasted baguette slices topped with melted Gruyère cheese, this hearty soup is perfect for a cozy meal that requires minimal hands-on time.
Ingredients
Scale
Soup Ingredients
- 4 large yellow onions, thinly sliced
- 4 cloves garlic, minced
- 2 tablespoons olive oil
- 4 cups beef broth
- 2 cups chicken broth
- 1/2 cup dry white wine
- 1 tablespoon Worcestershire sauce
- 4 sprigs fresh thyme
- 1 bay leaf
- Salt and pepper, to taste
Topping Ingredients
- 1 baguette, sliced into 1-inch pieces
- 2 cups grated Gruyère cheese
Instructions
- Prepare the Onions and Garlic: Peel and thinly slice the onions into even rings. Mince the garlic cloves carefully.
- Caramelize Onions and Garlic: Heat olive oil in a large skillet over medium-high heat. Add the sliced onions and minced garlic and sauté, stirring frequently, until the onions are golden brown and caramelized, about 15-20 minutes.
- Transfer to Slow Cooker: Move the caramelized onions and garlic into your slow cooker. Pour in the beef broth, chicken broth, dry white wine, and Worcestershire sauce.
- Add Herbs and Season: Add fresh thyme sprigs and the bay leaf to the slow cooker mixture. Season with salt and pepper to taste.
- Slow Cook the Soup: Cover the slow cooker and cook on low for 6 to 8 hours, or alternatively on high for 3 to 4 hours, allowing flavors to meld and deepen.
- Remove Herbs: Once cooking is complete, discard the thyme sprigs and bay leaf from the soup.
- Toast the Baguette: Preheat your oven to 400°F (200°C). Toast the baguette slices on a baking sheet until golden and crisp, approximately 5-7 minutes.
- Assemble Bowls: Ladle the hot soup into oven-safe bowls placed on a rimmed baking sheet. Top each bowl with a toasted baguette slice and a generous sprinkle of grated Gruyère cheese.
- Broil the Cheese Topping: Place the baking sheet with the soup bowls under the oven broiler until the cheese melts, bubbles, and turns golden brown, about 3-5 minutes.
- Serve: Carefully remove the bowls from the oven, optionally garnish with fresh thyme, and serve immediately while hot and bubbly.
Notes
- For deeper flavor, you can caramelize the onions longer but be careful not to burn them.
- Adjust the salt and pepper according to your preference, especially if your broth is already salted.
- The choice of cheese impacts the flavor; Gruyère is traditional, but Swiss or even mozzarella can work as substitutes.
- Using oven-safe bowls is crucial for broiling the cheese topping directly on the soup.
- If you don’t have a broiler, you can place the bowls under a hot grill or use a kitchen torch to melt the cheese.
