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Crockpot French Onion Soup

Crockpot French Onion Soup Recipe

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Prep Time 15 minutes
Cook Time 6 hours
Total Time 6 hours 15 minutes
Servings: 4 servings
Calories: 410
Ingredients Method Notes

Ingredients
  

  • 4 large yellow onions, thinly sliced
  • 3 tbsp unsalted butter
  • 1 tbsp olive oil
  • 1 tsp granulated sugar (optional)
  • 1 tsp salt
  • 1/2 tsp black pepper
  • 2 tbsp all-purpose flour
  • 1/2 cup dry sherry
  • 6 cups low-sodium beef broth
  • 1 tbsp Worcestershire sauce
  • 2 sprigs fresh thyme
  • 1 bay leaf
  • 8 slices French baguette (1/2 inch thick)
  • 8 oz Gruyère cheese, shredded

Method
 

  1. In a large Dutch oven over medium heat, melt butter with olive oil. Add onions, salt, pepper, and sugar (if using). Cook, stirring occasionally, until deeply golden and reduced, 25 to 30 minutes.
  2. Stir in flour and cook 1 minute. Pour in sherry, scraping up browned bits from the bottom, and simmer 2 minutes. Transfer to a slow cooker and stir in beef broth, Worcestershire, thyme sprigs, and bay leaf.
  3. Cover and cook on low 6 to 8 hours or high 3 to 4 hours. Remove thyme sprigs and bay leaf. Taste and adjust salt.
  4. Preheat broiler with a rack in the upper third. Arrange baguette slices on a baking sheet and broil until lightly golden, 1 to 2 minutes per side.
  5. Ladle soup into oven-safe bowls set on a rimmed baking sheet. Top each with a toast and about 1 oz shredded Gruyère. Broil 2 to 3 minutes until bubbly and spotted brown. Serve hot.

Notes

Cook time varies between 6 to 8 hours on low; the onions should be completely tender. High setting shaves the time to 3 to 4 hours. Use oven-safe bowls for broiling and keep a baking sheet underneath to catch cheese drips. Freeze leftover soup without bread for up to 3 months.