Slow Cooker French Onion Soup

Oh the weather outside is frightful! Seriously, can Spring make up its mind yet? One day the sun is out and shining a beautiful 80*. Then the next we have sub 40* temperatures with rain. The constant yo-yo has me craving some comfort food to warm the soul … and maybe my fingers.

With that said, here is a recipe for soup! Not just any soup, but the king of soups: French onion soup. You’ve probably ordered this dish once or twice while at a restaurant and just savored every last bite of this cheese-covered soup thinking to yourself “this is absolutely the best soup in the world.” Am I right? Of course I am because NOTHING beats a great crock of French Onion Soup on a cold, blistery day.

From the beefy broth, the flavorful caramelized onions, the broth-soaked bread to the cheese — the golden, bubbling layer of perfection to top of this amazing bowl of yumminess. While I think we can all admit how much we LOVE French Onion Soup, few and far between have actually made it at home. Even though it looks intricate (AKA a complex, tricky recipe), it’s actually quite EASY! PLUS, we made it even easier with our slow cooker version!

So what are you waiting for? Go make a pot. And enjoy this perfect soup all winter long… or you know, Spring, whichever tickles your fancy.



French Onion Soup

Course Soup
Servings 8 bowls
Author Courtney & Steve


Onion Mixture

  • 2 tbs Brown Sugar dark
  • 3 tbs Butter
  • 5 Yellow Onions quartered

Soup Mixture

  • 8 sprigs Thyme stripped
  • 1/4 cup Sherry
  • 1 tbs Worcestershire Sauce
  • 5 cloves Garlic minced
  • 1/4 cup Balsamic Vinegar
  • 1 cup Red Wine dry
  • 64 oz Beef Stock reduced sodium
  • 3 Bay Leaves


  • Baguette sliced
  • 2 cups Gruyere cheese shredded
  • 2 cups Mozzarella cheese shredded
  • 2 cups Swiss cheese shredded


  1. Melt butter in a large skillet over medium-low heat. Add onions, cooking until soft - stirring occasionally for about 15-20 minutes. Add sugar with salt & pepper to taste; continue to cook, stirring occasionally until onions are deep golden brown and caramelized, reducing heat slightly if onions seem to be browning too quickly (approximately 20 - 30 minutes).
  2. Add the ingredients from Step 1 (onion mixture) into your crockpot, combining with ingredients from Soup mixture. Stir until all ingredients are combined. Cover and cook on low for 6 to 8 hours. The longer you cook the soup, the more intense the flavors will be!
  3. Place the slices of baguette on a baking pan and toast (I use the broil part of my oven for approximately 2 minutes on each side).

  4. Portion the soup into oven-safe bowls and place on top a baking pan for ease. I then add a nice portion of Mozzarella & Swiss cheese into the mixture before placing my pieces of baguette. I top the baguette with generous amounts of Gruyere cheese. Place the bowls in the oven to bake at 350*F for approximate 20 to 30 minutes to melt the cheese.

    If you are like me, you like the crispy melted cheese - to achieve this, broil the soup bowls for an additional 2 to 3 minutes after baking so the cheese is bubbly & browned.

Recipe Notes

If you don't have crock bowls, I highly suggest you invest in some. I have found these on Amazon (affiliate link), but if you would like to search on your own a key thing to look out for is the handles. Some are hollow and crack/shatter with heat (just check your reviews) 🙂

Amazon Soup Crocks



  1. SEO Mechanic | 28th Apr 17

    This looks delicious

    • Courtney & Steve | 28th Apr 17

      It was and with the weather so up and down, soup is just what I needed.

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