Description
This Slow Cooker French Onion Soup is a comforting and rich classic dish made easy with a slow cooker. Sweet caramelized onions simmer in a flavorful broth with hints of red wine, herbs, and Worcestershire sauce. Topped with toasted baguette slices and melted Gruyere and Parmesan cheeses, this soup offers a perfect blend of deep flavors and creamy, cheesy goodness, ideal for a cozy meal.
Ingredients
Soup Ingredients
- 3 large yellow onions, thinly sliced
- 1/4 cup butter, cubed
- 2 teaspoons kosher salt
- 1 teaspoon fresh ground black pepper
- 8 cups beef broth or vegetable broth
- 1/2 cup red wine
- 1 bay leaf
- 1 teaspoon dried thyme
- 2 beef bouillon cubes
- 2 teaspoons Worcestershire sauce
Toppings
- 16 slices French Baguette, sliced 1/4-inch thick
- 8 ounces Gruyere cheese, grated
- 1/4 cup grated Parmesan cheese
Instructions
- Prepare Onions: Place the thinly sliced onions, cubed butter, kosher salt, and fresh ground black pepper into your slow cooker. Cook on high for 3-4 hours until the onions are tender and caramelized.
- Add Broth and Seasonings: Stir the cooked onions, then add in the beef or vegetable broth, red wine, bay leaf, dried thyme, beef bouillon cubes, and Worcestershire sauce. Mix well to combine all flavors.
- Continue Cooking: Cook on high for an additional 2-3 hours until the onions are fully cooked down and the flavors have melded together beautifully.
- Prepare for Serving: Remove the bay leaf from the soup. Ladle the hot soup into oven-safe bowls or ramekins.
- Broil with Cheese and Bread: Preheat your oven to the broil setting. Top each bowl with two slices of French baguette and a generous amount of grated Gruyere and Parmesan cheese. Place the bowls on a baking sheet and broil for 2-3 minutes or until the cheese is melted, bubbly, and golden brown. Serve immediately.
Notes
- You can substitute vegetable broth to make it vegetarian, but the flavor will be less traditional.
- Use oven-safe bowls or ramekins to broil the cheese topping safely.
- Keep an eye on the soup under the broiler to prevent burning the cheese.
- Leftovers can be refrigerated for up to 3 days and reheated gently on the stove.
- For a deeper flavor, caramelize onions longer on low heat before adding broth in the slow cooker.
