Description
A hands-off, slow-cooker version of classic French onion soup that delivers deep, caramelized onion flavor and a rich, cheesy crust without the constant stirring.
Ingredients
Scale
- 6 large yellow onions (about 3 lbs / 1.4 kg), sliced into half-moons
- 4 tablespoons unsalted butter
- 4 cloves garlic, minced
- 2 tablespoons all-purpose flour
- 4 cups low-sodium beef broth
- ½ cup dry white wine (such as Sauvignon Blanc or Pinot Grigio)
- 1 tablespoon Worcestershire sauce
- 3 sprigs fresh thyme (or 1 teaspoon dried)
- 1 bay leaf
- 1 teaspoon salt (plus more to taste)
- ½ teaspoon black pepper (plus more to taste)
- 1 loaf French bread or baguette, sliced into ½-inch rounds
- 2 cups Gruyere cheese, shredded
- ½ cup Parmesan cheese, freshly grated
- 2 tablespoons fresh parsley, chopped
Instructions
- Peel and slice the onions into thin half-moons.
- In a large skillet over medium heat, melt the butter. Add the sliced onions and cook for 5-7 minutes until they start to soften and release moisture.
- Add the minced garlic and flour to the skillet. Stir constantly for 1 minute to coat the onions.
- Transfer the onion mixture to a 6-quart slow cooker.
- Add the beef broth, white wine, Worcestershire sauce, thyme sprigs, bay leaf, salt, and pepper. Stir well to combine.
- Cover and cook on LOW for 6-8 hours (or HIGH for 3-4 hours if short on time).
- Once cooked, remove the thyme sprigs and bay leaf. Taste and adjust seasoning. If the soup is too thin, simmer uncovered on HIGH for 15-20 minutes to reduce.
- Preheat the broiler. Slice the baguette and toast the slices lightly under the broiler for 1-2 minutes per side until golden and crisp.
- Ladle the hot soup into broiler-safe bowls.
- Place a slice of toasted baguette on top of each bowl.
- Sprinkle generously with the Gruyere and Parmesan cheese mixture.
- Place the bowls on a baking sheet and broil for 2-3 minutes, watching closely, until the cheese is bubbly and golden brown.
- Garnish with fresh parsley and serve immediately.
Notes
Do not use pre-shredded cheese as it contains anti-caking agents that prevent smooth melting. Toast the bread before adding cheese to prevent it from becoming mushy. Watch the cheese closely under the broiler as it burns quickly. The soup base can be frozen for up to 3 months without the bread and cheese.
- Prep Time: 15 minutes
- Cook Time: 6-8 hours
- Category: Main Course
- Cuisine: French
Nutrition
- Serving Size: 1 bowl with bread an
- Calories: 450
- Sugar: 8
- Sodium: 680
- Fat: 22
- Saturated Fat: 12
- Carbohydrates: 35
- Fiber: 4
- Protein: 18
Keywords: crockpot french onion soup, winter recipe, slow cooker soup, gruyere cheese, comfort food, easy dinner