• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

Simply So Good

  • Home
  • About
  • Recipes
  • Contact
You are here: Home / Recipes / Soups / Slow Cooker French Onion Soup

Slow Cooker French Onion Soup

October 22, 2021 Updated March 16, 2022 Leave a Comment

22 shares
  • Share
  • Tweet
Jump to Recipe Print Recipe
overhead shot of french onion soup with thyme sprigs on top of gruyere toast

Slow Cooker French Onion Soup is everything you dream of in a French onion soup.  The slow cooker will slowly caramelize the onions to perfection.  Just add broth and fresh herbs and continue to slow cook.  The onions will melt in your mouth and of course, topped with baguette and oozy French Gruyere cheese.

overhead shot of french onion soup with thyme sprigs on top of gruyere toast

French Onion Soup is one of my favorite warming soups for fall and winter.  Using a slow cooker creates the perfect caramelized onions along with a deep, flavorful broth.  The toasted baguette will soak up the rich broth topped with bubbling gruyere.  

 

Caramelizing the Onions

Sliced onions on a board with garlic, knife, and coconut sugar on the side

Slicing the onions will be the most difficult part of this recipe.  It’s not hard, but you will probably shed a tear or two.  Using a mandolin will make the slicing a breeze.  I like to use sweet Walla Walla onions.  You can use whatever sweet onion you can find.  Slice 3-4 large onions.  

Several sliced onions, butter, onion, garlic, measuring spoons

You will, also, need 1/2 cup of unsalted butter, 3 large cloves of garlic, 2 tablespoons coconut sugar, or brown sugar (this will help brown the onions nicely you can omit the sugar altogether if you wish).  Lastly just 1/2 teaspoon salt.  The broth used will add more salt to the soup.  It’s best to under salt because you can always add more to your liking.  Once the salt is in the soup, it can not be removed!  

Slow Cooker French Onion Soup

Butter chunks in crock pot insert for french onion soup1
French onion soup in a Crockpot filled with sliced onons2
French onion soup in a Crockpot with onion slices sprinkled with coconut sugar and salt3
For french onion soup Sliced onions in a crockpot with a garlic press adding garlic4
For french onion soup Onions cooked down with broth5
  1. In the bowl of a crockpot melt butter. 
  2. Add sliced onions.
  3. Sprinkle with the coconut sugar, 1/2 tsp. salt.  Stir to coat onions. 
  4. Add chopped garlic to the top of the onions.   Cook on low for 6 hours. Stirring every 30 minutes or so.  
  5. The onions will be reduced significantly in size and will be more golden in color.  Now that the onions are the perfect golden color, add the chicken and beef broth, 3-4 sprigs of fresh thyme, and a large bay leaf. Continue to cook for an additional 8 hours.  

In the meantime:

  • Slice the baguette into 1-inch slices.  Butter both sides of the bread and place on a hot griddle or skillet.  Toast both sides.  
  • Grate the gruyere cheese and set it aside.

The Finishing Touches

Thyme removed from crockpot
Adding fresh thyme and parsley to french onion soup
  • After the soup has cooked for 8 hours, remove the thyme springs and bay leaves.  Discard.
  • Add in fresh chopped thyme and parsley.  

Serving French Onion Soup

Ladle the hot soup into individual crocks, bowls, or mugs.  Top with enough of the toasted baguette to cover the top.  Load on the shredded gruyere and place under a hot broiler and cook until the cheese is melted and beginning to bubble.  Enjoy the warmth of this classic French Soup.

Just check out this oozy gooey cheese stretch.  Best! ❤️

overhead shot of french onion soup with thyme sprigs on top of gruyere toast
0 from 0 votes
Print

Slow Cooker French Onion Soup

Slow Cooker French Onion Soup is everything you dream of in a French onion soup.  The slow cooker will slowly caramelize the onions to perfection.  Just add broth and fresh herbs and continue to slow cook.  The onions will melt in your mouth and of course, topped with baguette and oozy French Gruyere cheese.

Course Appetizer, Dinner
Cuisine American, French
Keyword Crockpot French Onion Soup, French Onion Soup, Onion Soup, Slow Cooker French Onion Soup
Prep Time 15 minutes
Cook Time 12 hours
Servings 8 Servings
Calories 366 kcal
Author Janet Barton

Ingredients

  • 3-4 large sweet onions organic, cut in half and sliced 1/8-1/4 inch thick
  • 1/2 cup unsalted butter
  • 1-2 tablespoons coconut sugar depending how sweet onions are
  • 1/2 teaspoon salt
  • 3 cloves garlic minced
  • 4 cups chicken bone broth
  • 4 cups beef bone broth
  • 1-2 tablespoons Worcestershire sauce
  • fresh thyme
  • 1 bay leaf
  • salt
  • fresh ground white pepper
  • fresh parsley
  • 1 loaf French Baguette Slice into 1-inch thick slices
  • 2-3 cups Gruyere cheese Shredded

Instructions

  1. In the bowl of a crockpot melt butter. Add sliced onions, coconut sugar, 1/2 tsp. salt. Stir to coat onions. Add minced onions to the top of the onions.
  2. Cook on low for 4-5 hours. Stirring every 30 minutes or so.

  3. Add broths, about 4 sprigs of fresh thyme and 1 bay leaf.

  4. Cover and continue to cook on low for an additional 8 hours.
  5. Before serving add Worcestershire sauce to taste. Season with salt and white pepper and additional fresh herbs.
  6. Slice baguette into 1-inch slices. Butter both sides and place on a hot griddle or skillet until golden brown.

  7. Pour steaming hot soup into serving bowls. Top with 1-2 slices of baguette (enough to cover the top of the soup). Divide shredded gruyere cheese over the top of the baguette. Place under a broiler until cheese begins to bubble and is completely melted. Serve.

Recipe Notes

  • Soup can cook for as long as 12 hours on low. 
  • Can use 8 cups vegetable stock in place of Chicken and Beef broth.  
  • I like to cook the onions during the day, then add the broth and cook through the night.
  • Soup can be cooled and refrigerated for 3-4 days. Reheat when ready to serve.
  • This recipe can serve up to 8 depending on the size of bowls and amounts used per serving.
Nutrition Facts
Slow Cooker French Onion Soup
Amount Per Serving
Calories 366 Calories from Fat 216
% Daily Value*
Fat 24g37%
Saturated Fat 14g70%
Trans Fat 1g
Polyunsaturated Fat 2g
Monounsaturated Fat 7g
Cholesterol 67mg22%
Sodium 553mg23%
Potassium 188mg5%
Carbohydrates 19g6%
Fiber 1g4%
Sugar 2g2%
Protein 19g38%
Vitamin A 670IU13%
Vitamin C 1mg1%
Calcium 371mg37%
Iron 1mg6%
* Percent Daily Values are based on a 2000 calorie diet.

You May Also Love

Pumpkin Apple soup in a bowl
Slices of No-knead Partially sliced Green Chile Cheddar Bread
crockpot burrata French onion soup
baked no-knead pumpkin harvest bread with a cinnamon stem in the middle. white and orange mini pumpkins in background

Share this:

  • Click to share on Twitter (Opens in new window)
  • Click to share on Facebook (Opens in new window)

Related

Filed Under: Soups, Vegetarian

Previous Post: « Most Popular Halloween Recipes
Next Post: Giant Cheddar Twists »

Reader Interactions

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Recipe Rating




This site uses Akismet to reduce spam. Learn how your comment data is processed.

Primary Sidebar

About Me

Janet Barton

Hi I'm Janet and this is where I share my delicious made-from-scratch seasonal recipes that I make at home for my family every day.

I believe cooking from scratch, using unprocessed and whole foods is an important part of healthy eating. My goal is to help you create amazing recipes by providing easy step-by-step photos and instructions.

Read More »

Trending Recipes

  • Lemonade and raspberry lemonade in tall glasses Old Fashioned Lemonade
  • No-knead Crusty Bread in a Dutch oven No-knead Crusty Bread
  • Lemon Curd Ice Cream in bread pan with spoon Lemon Curd Ice Cream
  • Glass of almond milk with 2 gray striped straws on wood board with container of almond milk in background Quick Homemade Almond Milk
  • Several chocolate drop cookies on white background Chocolate Drop Cookies
  • Oatmeal cookies on cookie rack Old-Fashioned Oatmeal Raisin Cookies
  • pink iced heart sugar cookies Sour Cream Sugar Cookies
  • vanilla and chocolate party cakes for kids Vanilla and Chocolate Party Cakes for Kids
  • Kalamata olive fouggase on marble with dipping sauce Kalamata Olive and Rosemary Fougasse with Fresh Herb and Pepper Dipping Oil
  • pan of frozen lemon curd ice cream with ice cream scoop No-Churn Lemon Curd Ice Cream

Subscribe to our email list for exclusive tips and recipes

  • Facebook
  • Instagram
  • Pinterest
  • RSS
  • Twitter

Latest on Instagram

Follow on Instagram


Footer

Featured on

The Daily Meal Logo The foodgawker-logo reddit Logo BuzzFeed Logo halfbaked Harvest Logo Browneyed Baker Logo BLOGHER Logo FOOD52 Logo University of Washington Logo sheknows Logo

Copyright © 2022 Janet Barton
Privacy Policy

 

Loading Comments...