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Crockpot French Onion Soup



Crockpot French Onion Soup is a great meal to have cooking on a busy night.  You can prep everything ahead and have it in the slow cooker all day.  No fuss is the way I like it around here and this soup is just that–no fuss!  This sweet onion soup is delicious with it’s rich beef stock, caramelized sweet onions, hint of thyme and cheesy top layer.  If it’s been a while since you enjoyed a bowl of french onion soup, you need to give this one a try.  It’s a winner! Crockpot French Onion Soup | KitchenCents.com This Crockpot French Onion Soup is great for those days when you know you won’t have a lot of time.  You can prep all the ingredients in the morning, or night before, and have them ready for the slow cooker.  The full printable recipe is at the bottom of this post. Below you’ll find step-by-step pictures.  Start by cutting all the onions with the grain.  The grain runs from the root to the top of the onion.  Cutting the onions this will help them stay intact during the cooking process.  Add the onions to the crockpot, top with butter and salt, then let it cook… and cook… and you guessed it, COOK!  As the onions heat they will begin to cook down and eventually brown.  Stirring occasionally will insure the onions are cooking evenly and not burning.  When the onions begin to turn light brown, the sugars are developing which causes them to caramelize.  This is the golden ticket!  Once the onions are adequately caramelized (this takes about 6-8 hours on low or 4-5 on high), add fresh thyme, beef broth, Worcestershire sauce, salt/pepper and a cornstarch slurry ( 2 tablespoons cornstarch to 1/4 cup cold water), then you’re almost done.  Heat on high until thickened (about 30-45 minutes depending on how cold your broth is). Crockpot French Onion Soup | KitchenCents.com Dish the soup into oven safe bowls and top with croutons (my personal favorite because they are crunchy–when added to this soup they soften without turning into complete mush) and cheese.  Broil for just a minutes or so until the cheese is ooey gooey and begins to brown. YUM! Crockpot French Onion Soup | KitchenCents.com When onions are cooked for a long time they caramelize and become so sweet.  That’s what makes this classic broth-y soup light yet filling and delicious.  Everyone who tries a bowl will think you slaved over a pot of caramelizing onions for hours–little will they know 😉 . Crockpot French Onion Soup | KitchenCents.com
Crockpot French Onion Soup

Crockpot French Onion Soup

Yield: 8 servings
Prep Time: 10 minutes
Cook Time: 6 hours
Total Time: 6 hours 10 minutes

This Crockpot French Onion soup is delicious with it's rich beef stock, caramelized sweet onions, hint of thyme and cheesy top layer.


  • 5-6 medium onions, about 3-4 lbs
  • 1/4 cup butter
  • 3-4 sprigs fresh thyme, on the steam or finely chopped (or 1/2 teaspoon dried)
  • 8 cups beef broth
  • 2 Tablespoons Worcestershire sauce
  • Salt & Pepper
  • cornstarch slurry, 2 Tablespoons cornstarch and 1/4 cup cold water
  • slices croutons, bread or baguette
  • slices cheese, (provolone, Gruyere or Swiss)


  1. Slice onions along grain (root to top). Place in crockpot. Top with butter and sprinkle with about a 1/2 teaspoon of salt. Cook on low for 6-8 hours or on high for 4-5 hours. Onions will begin to sweat and cook down. They will turn golden brown--become sweet and caramelized.
  2. Once the onions have caramelized add thyme, beef broth, Worcestershire sauce, salt & pepper to taste and cornstarch slurry. Cook on high for 30-45 minutes until hot and slightly thickened.
  3. Pour into oven safe bowls, top with croutons and cheese slice. Broil in oven 1-2 minutes until cheese is melted and begins to brown. Serve immediately.


Stir onions occasionally will insure even cooking and prevent onions from burning.

If onions seem to be sticking to the crockpot you may add a 1/2 cup beef broth.

Nutrition Information:
Yield: 8 Serving Size: 1
Amount Per Serving: Calories: 369Total Fat: 13gSaturated Fat: 7gTrans Fat: 0gUnsaturated Fat: 5gCholesterol: 34mgSodium: 1421mgCarbohydrates: 49gFiber: 2gSugar: 6gProtein: 14g
  What do you like to add on top of your French Onion Soup?  What’s your favorite caramelized onion dish? Crockpot French Onion Soup | KitchenCents.com

20 thoughts on “Crockpot French Onion Soup”

  1. French Onion Soup is my husband’s favorite! I’ve never made it in the slow cooker but may give it a try after reading this. Looks a lot easier than stirring it on the stove.

    • HAHA… that is the number one reason I love this recipe. We love french onion soup but when making it on the stove, you’re stuck stirring it for a long time.

  2. I haven’t had a french onion soup in forever! I love my crockpot and how easy meals come out, so I can just pretty much cut down on the normal time of cooking and cleaning. I’m going to have to make this soon!

  3. I love the addition of Worcestershire sauce in the broth–I’ve never done that before. I’ll have to try your recipe out the next time I’m in the mood for french onion soup!


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