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A steaming hot bowl of Crockpot French Onion Soup, with caramelized onions and melted cheese, is the featured image for this delicious recipe.

Ultimate Crockpot French Onion Soup

This classic French Onion Soup recipe is perfected in the Crockpot, with caramelized onions, a rich broth, and a cheesy, crusty topping.
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Prep Time 20 minutes
Cook Time 11 hours
Total Time 11 hours 20 minutes
Servings: 4
Course: Soup
Cuisine: French
Calories: 450
Ingredients Equipment Method Notes

Ingredients
  

  • 6 large yellow onions, thinly sliced
  • 4 cups beef broth
  • 2 cups chicken broth
  • 1/2 cup dry white wine
  • 2 tablespoons balsamic vinegar
  • 2 bay leaves
  • 2 sprigs fresh thyme
  • 1 teaspoon salt
  • 1/2 teaspoon black pepper
  • 8 slices of crusty bread
  • 2 cups shredded Gruyère cheese

Equipment

  • Crockpot
  • Oven
  • Oven-safe bowls
  • Slicing knife
  • cutting board

Method
 

  1. Place the sliced onions in a Crockpot and cook on low for 8-10 hours, stirring occasionally, until the onions are caramelized and golden brown.
  2. Add the beef broth, chicken broth, white wine, balsamic vinegar, bay leaves, and thyme to the Crockpot. Stir to combine and season with salt and pepper.
  3. Cover the Crockpot and continue cooking on low for an additional 2-3 hours, allowing the flavors to meld and the broth to develop.
  4. Preheat your oven's broiler. Ladle the soup into oven-safe bowls and top each with a slice of crusty bread and a generous amount of shredded Gruyère cheese.
  5. Place the bowls under the broiler for 2-3 minutes, or until the cheese is melted and bubbly.
  6. Serve the Crockpot French Onion Soup hot, garnished with additional fresh thyme if desired.

Notes

The key to this recipe is the slow, gentle cooking process in the Crockpot, which allows the onions to caramelize and develop a deep, rich flavor. For best results, use a combination of beef and chicken broth, and don't be afraid to experiment with different types of crusty bread and cheese toppings.