Introduction
Slow Cooker French Onion Soup is a timeless classic that brings warmth and comfort in every bowl. This rich and savory soup is made with caramelized onions, a flavorful beef broth, and topped with gooey melted Gruyère cheese and crispy bread. The slow cooking process allows the onions to develop their natural sweetness, creating a deep, complex flavor that is simply irresistible.
Why You’ll Love This Recipe
Perfect for Any Occasion: Whether it’s a chilly evening at home, a cozy gatherin.
Effortless Preparation: With the use of a slow cooker, this recipe requires minimal hands-on time. Simply prepare the ingredients, set them in the slow cooker, and let it do the work while you go about your day.
Rich Flavor: The long cooking time enhances the sweetness of the onions and melds the flavors beautifully, resulting in a comforting and hearty soup.
Customizable: Feel free to adjust the ingredients to suit your taste. You can experiment with different types of cheese, add herbs, or even include a splash of brandy for an extra layer of flavor.
Ingredients
3 pounds onions (about 6 large onions), sliced thinly
1/2 cup (4 oz) butter, melted
2 cloves garlic, minced
1/2 cup dry sherry wine (optional)
8 cups beef stock/broth
1 bay leaf
1/4 tsp dry thyme (or 3 sprigs fresh, optional)
Salt and pepper to taste (omit salt if using salted broth)
Baguette, sliced (consider using French bread for less holey texture)
8 oz Gruyère cheese, shredded (divided)
Instructions
Step 1: Prepare the Onions
Slice the Onions:
Cut the onions in half and slice them thinly.
Combine in Slow Cooker:
Place the sliced onions in the slow cooker. Add the melted butter and stir well to coat all the onions.
Cook Overnight:
Set the slow cooker to low and cook for 10-12 hours overnight.
Step 2: Add Flavor
Morning Addition:
In the morning, add the minced garlic to the onion mixture. Stir in the dry sherry (if using) and scrape the bottom to dissolve any browned bits.
Add Remaining Ingredients:
Throw in the thyme, bay leaf, and beef broth. Stir well to combine. Cook on low for 8-10 hours or on high for 4-6 hours, depending on your time constraints.
Step 3: Prepare the Bread
Preheat Oven:
Preheat your oven to 400ºF.
Slice and Oil the Bread:
Slice the baguette into 1/2-inch thick slices. Brush both sides lightly with olive oil.
Bake the Bread:
Arrange the slices on a baking sheet and bake for 6-8 minutes until golden brown at the edges. Flip the bread and bake for an additional 2 minutes if needed.
Step 4: Broil and Serve
Set Oven to Broil:
Once the soup is ready, set your oven to broil.
Assemble the Soup:
Pour the soup into bowls, filling them about 3/4 full. Sprinkle a bit of Gruyère cheese on top, lay the toasted bread slices over the cheese, and sprinkle the remaining cheese on top.
Broil:
Broil for 2-3 minutes until the cheese is lightly browned and bubbling.
Storage Methods
Refrigeration
Cool Down:
Allow the soup to cool to room temperature before storing. This helps prevent condensation and keeps the soup from becoming watery.
Use an Airtight Container:
Transfer the soup to an airtight container. Make sure it’s sealed tightly to prevent air exposure.
Label:
Write the date on the container so you can keep track of freshness.
Store:
Place the container in the refrigerator. The soup can be stored for up to 3-4 days.
Freezing
Portion Out:
If you want to store the soup for a longer period, consider portioning it into smaller containers or freezer-safe bags for easy reheating.
Avoid Cheese Topping:
It’s best to freeze the soup without the cheese topping. You can add the cheese when reheating for the best texture and flavor.
Use Freezer-Safe Containers:
Ensure the containers or bags are suitable for freezing. Leave some space for expansion.
Label:
Write the date on the container or bag.
Store:
Freeze for up to 3 months. For best quality, consume within this time frame.
Reheating
Refrigerated Soup:
Reheat on the stovetop over medium heat until warmed through, or microwave in short intervals, stirring in between.
Frozen Soup:
Thaw in the refrigerator overnight before reheating, or use the microwave on the defrost setting. Then heat on the stovetop or microwave until hot.