Slow Cooker French Onion Soup Recipe
Delicious Caramelized Onions Made Easy

Two bowls of French Onion Soup
#soupsofineSlow Cooker French Onion Soup Recipe

This French onion soup recipe helps you create slowly caramelized onions and a rich-flavored broth. Each serving is topped with toasted baguette slices under cheese melted to a bubbly golden brown. It's easy and absolutely delicious!

The Healing Power of Onions

We have loved onions for at least 6,000 years, making them one of our most ancient foods. Not only are we crazy about their flavor and the contributions they make to our favorite recipes, but we have long relied on their wonderful curing properties. Ancient medical writings celebrated the healing power of onions. It's even reported that Nero ate onions to stop a sore throat. 

Today, we know that onions are full of anti-cancer chemicals. They can also help prevent heart disease, help balance blood sugar levels, and ward off Alzheimer's disease. 

Enjoy! Onions are great for you, and this lovely soup is a delicious way to enjoy their health-giving goodness!

Bowl of French Onion Soup

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Prep Time: 15 minutes            Cook Time: 5 to 7 hours HIGH           Total Time: 5 hours 30 minutes             Serves: 4

Ingredients for Slow Cooker French Onion Soup Recipe

6-7 large yellow onions, peeled and halved top to bottom, with flat side down cut lengthwise into medium-thin slices

3 tablespoons melted butter

1 teaspoon kosher salt

1/4 cup dry sherry

3 cups beef stock

1-1/2 cups water

1 bay leaf

1/2 teaspoon dried thyme

1-inch slices of French baguette (8-12 pieces) 

2 cups grated Gruyère or Mozzarella cheese

3-4 sprigs of fresh thyme, use leaves for garnish

Bowl of Slow Cooker French Onion Soup #SoupSoFine

Directions for Slow Cooker French Onion Soup Recipe

1. Add: In a 6-quart slow cooker, add the sliced onions.

2. Add: Add melted butter. Toss onions with two wooden spoons to evenly coat them with butter.

3. Sprinkle with salt.

4. Cook on HIGH: With lid on, cook for 4-6 hours on HIGH. Onions should be wilted and golden brown.

5. Heat in saucepan: In a small saucepan, add dry sherry and 1 cup beef stock. Heat on medium high for about 5 minutes to allow some of the alcohol to evaporate.

6. Add: Add the heated mixture to the slow cooker. Also add the water, remaining two cups of beef stock, dried thyme, and bay leaf.

7. Cook on HIGH: Cook on HIGH for 1-1/4 hours.

8. Remove bay leaf and discard.

9. Reduce heat to LOW: Turn slow cooker to LOW and let soup simmer while you toast the baguette slices.

10. Toast bread: Preheat oven to 350°F. Lightly coat a glass baking dish with cooking spray and arrange bread slices in a single layer. Bake for about 10 minutes or until edges are toasted to a golden brown.

11. Before you set oven to BROIL, position your top rack about 12 inches from the broiler.

12. Ladle soup: Cover a rimmed baking sheet with aluminum foil to make clean up easy. Ladle soup into broiler-safe bowls or crocks until each is a little more than half full.

13. Finish layers: Evenly space bowls on the baking sheet, and place 2-3 baguette slices, toasted side down, on top of the soup. Bread should not overlap. Sprinkle at least 1/2 cup of cheese over the bread.

14. Broil: Broil for 3 to 4 minutes or until the cheese is melted and golden brown around the edges.

15. Enjoy!


Hays, Rebecca. "Best French Onion Soup." Cook's Illustrated All-Time Best Soups & Stews, 2014.

Lang, Susan S. "Onion a Day Keeps Doctor Away? Cornell Researchers Find Some Onions Do Indeed Have Excellent Anti-cancer Benefits | Cornell Chronicle." Home | Cornell Chronicle. Accessed February 10, 2018.

Locke, Robert. "10 Benefits of Onion That Will Surely Surprise You." Lifehack. Last modified April 22, 2014.

Mehta, Dr. Indu. "Origin and History of Onions." UGC Approved Journal. Accessed February 10, 2018.

Two bowls of Slow Cooker French Onion Soup Recipe 

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