Simple Slow Cooker French Onion Soup

4.4 from 23 votes

Posted December 2, 2020Last Updated October 25, 2024

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Onions are caramelized in the slow cooker, then combined with beef broth in this easy soup recipe. Topped off with toasted baguette slices and melted cheese, this simple soup is sure to become a family favorite.

If you love caramelized onions, but don’t want to stand around stirring onions forever, you’re going to love this Simple Slow Cooker French Onion Soup.

Yes, it takes awhile to caramelize onions in the slow cooker too, but when you do, you can walk away and come back hours later to perfectly golden, soft and flavorful onions.

And of course, French onion soup is the perfect way to showcase caramelized onions. In fact, as the name suggests, onions are the star of this recipe.

Trust me, once you’ve made French onion soup this way, you’ll never go back to the stove-top method!

Even people who say they don’t like onions (like my husband), love this soup. In fact, he says it’s one of his favorites and requests it often. I love onions, so I’m always happy to oblige.

As much as I love onions, I have to admit that my favorite thing about this soup are the crusty baguette slices with melted cheese.

The recipe calls for Gruyere, but if that’s not available, shredded mozzarella will do the trick. Fontina is another good choice that melts easily and tastes amazing.

There are so many things I love about this soup, including the fact that it’s kind of fancy and gourmet, yet so simple and economical to make.

With the exception of the cheese, you really won’t find less expensive ingredients than beef broth, onions and day old bread.

This Simple Slow Cooker French Onion Soup is a regular menu item at our house during the chilly winter months. It’s true comfort food that never gets old.

Be sure to save this Simple Slow Cooker French Onion Soup recipe to your favorite Pinterest board for later.

Here’s what you’ll need to make Simple Slow Cooker French Onion Soup

Butter
Produce: fresh thyme, onions
Spices: bay leaves, salt and pepper
Sugar
Beef broth
Worcestershire sauce
Baguette slices
Gruyere cheese

Simple Slow Cooker French Onion Soup

4.35 from 23 votes

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Course: Soups

Cuisine: French

Prep Time: 20

Cook Time: 8

Total Time: 8 20

Servings: 8 -10 servings

Calories: 455kcal

Author: Danelle

Ingredients

1/4 cup butter softened
6-8 sprigs fresh thyme
1 bay leaf
5-6 large yellow onions thinly sliced
1 tablespoon sugar
8 cups low-sodium beef broth
1 tablespoon Worcestershire sauce
1 teaspoon salt
1 teaspoon pepper
1 small baguette sliced
4-6 ounces Gruyere cheese shredded

Equipment

Slow Cooker
Mandoline
Baking Sheets
Parmesan Cheese Grater

Instructions

Place butter, thyme, bay leaf and sliced onions in a lightly greased slow cooker. Stir to combine, then sprinkle with sugar. Cover and cook on high for 6-8 hours, or until onions are soft and dark golden brown. Stir occasionally during cooking.
Discard thyme sprigs and bay leaf. Add beef broth, Worcestershire sauce, salt and pepper. Cover and cook on high for 30-60 more minutes.
Preheat broiler. Arrange baguette slices on a large baking sheet. Top with shredded cheese. Broil for about 2 minutes, or until cheese melts and beings to turn golden.