How to Make Slow Cooker French Onion Soup - A Step-by-Step Guide

French onion soup is a classic French dish that is rich, flavorful, and perfect for a cozy night in. Made with caramelized onions, beef broth, and topped with melted cheese and crusty bread, this soup is a comfort food favorite that will warm you from the inside out. While traditional French onion soup requires a lot of time and attention to caramelize the onions, this slow cooker version simplifies the process, making it a perfect meal for busy weeknights.

The slow cooker method allo...

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Ingredients

  • 6 tablespoons butter
  • 4 large yellow onions, sliced and separated into rings
  • 1 tablespoon white sugar
  • 2 cloves garlic, minced
  • ½ cup cooking sherry
  • 7 cups reduced-sodium beef broth
  • 1 teaspoon sea salt, or to taste
  • ¼ teaspoon dried thyme
  • 1 bay leaf
  • 8 slices of French bread
  • ½ cup shredded Gruyere cheese
  • ⅓ cup shredded Emmental cheese
  • ¼ cup freshly shredded Parmesan cheese
  • 2 tablespoons shredded mozzarella cheese

Information

  • Prep Time: 30 mins
  • Cook Time: 4 hrs 45 mins
  • Total Time: 5 hrs 15 mins
  • Servings: 8

  • Heat butter in a large, heavy pot over medium-high heat. Add onions; cook and stir until translucent, about 10 minutes. Sprinkle onions with sugar; reduce heat to medium. Cook, stirring constantly, until onions are soft and caramelized, at least 30 minutes. Stir in garlic and cook until fragrant, about 1 minute.
  • Stir sherry into onion mixture; scrape the bottom to dissolve the small bits of browned food. Transfer onions into a slow cooker and pour in beef broth. Season with sea salt; stir in thyme and bay leaf. Cover and cook on Low for 8 to 10 hours or on High for 4 to 6 hours.
  • Preheat the oven broiler about 10 minutes before serving. Set an oven rack about 8 inches from the heat source.
  • Arrange bread slices on a baking sheet; broil until toasted, 1 to 2 minutes per side.
  • Lightly toss Gruyere, Emmental, Parmesan, and mozzarella cheeses in a bowl. Fill oven-safe soup crocks 3/4 full with onion soup and float a bread slice in each bowl. Top each with about 2 tablespoons cheese mixture.
  • Place filled bowls onto a baking sheet and broil until cheese topping is lightly browned and bubbling, about 2 minutes.
  • Nutrition

    442 cal.

    • Total Fat: 16g
    • Saturated Fat: 9g
    • Cholesterol: 38mg
    • Sodium: 1539mg
    • Total Carbohydrate: 57g
    • Dietary Fiber: 3g
    • Total Sugars: 10g
    • Protein: 18g
    • Vitamin C: 4mg
    • Calcium: 222mg
    • Iron: 4mg
    • Potassium: 283mg