Slow Cooker French Onion Soup (Printable)

Rich and comforting French classic with caramelized onions in savory broth, topped with crusty bread and melted Gruyère.

# What You Need:

→ Vegetables

01 - 5 large yellow onions, thinly sliced
02 - 2 cloves garlic, minced

→ Liquids

03 - 6 cups beef broth
04 - 1/2 cup dry white wine

→ Dairy

05 - 2 cups shredded Gruyère cheese
06 - 2 tablespoons unsalted butter

→ Breads

07 - 1 baguette, sliced into 1/2-inch rounds

→ Seasonings

08 - 1 teaspoon salt
09 - 1/2 teaspoon black pepper
10 - 2 teaspoons fresh thyme leaves
11 - 1 bay leaf

# Steps:

01 - Melt butter in a large skillet over medium heat. Add sliced onions and cook, stirring frequently, until soft and lightly golden, approximately 10-15 minutes.
02 - Stir minced garlic into the caramelized onions and continue cooking for 1 minute until fragrant.
03 - Transfer the onion mixture to the slow cooker. Pour in beef broth, white wine, and add thyme, bay leaf, salt, and pepper. Stir thoroughly to incorporate all ingredients.
04 - Cover and cook on low heat for 6-8 hours until onions achieve deep caramelization and flavors have fully melded. Remove and discard the bay leaf before serving.
05 - Preheat broiler 20 minutes before serving. Arrange baguette slices on a baking sheet and toast until golden brown, 1-2 minutes per side.
06 - Ladle hot soup into oven-safe bowls. Place a toasted baguette slice on top of each bowl and generously cover with Gruyère cheese.
07 - Arrange bowls on a baking sheet and broil until cheese becomes bubbly and golden brown, approximately 2-3 minutes. Serve immediately, garnished with additional thyme if desired.

# Expert Advice:

01 -
  • The slow cooker does all the heavy lifting, transforming humble onions into something extraordinary
  • Its incredibly budget friendly yet tastes like a restaurant quality starter
  • The leftovers somehow taste even better the next day
02 -
  • Don't rush the initial onion cooking step, it builds the flavor foundation
  • Use truly oven safe bowls, or you'll have a broken dish mess on your hands
03 -
  • Add a splash of sherry right before serving for an extra layer of complexity
  • Use ramekins if you don't have oven safe bowls, just watch them closely under the broiler

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