Slow Cooker French Onion Soup

Slow Cooker French Onion Soup by Diethood

I am running a bit late today. I have my reasons; blog post scheduling conflict is one of them. A sick baby is another. I know, ’tis the season for colds, but you just pray that it will skip your kids. And then it doesn’t.
Wish I could give her some of this soup and make it go away. According to my Grandma, onions ward off the flu…
So, I took out the slow cooker last week. I was really looking forward to doing so because I prefer a slow cooked meal, that will be warm and ready just as everyone starts to come home. What I don’t like is rushing, stirring above the stove minutes before dinner, or preparing dinner hours before it’s time to eat and then having to reheat it in the microwave.
I wasn’t sure how this soup was going to turn out in the slow cooker, but I went ahead with the idea and, since I am sharing it here, you know it was a really good call. A delicious one, at that.
Really, though, I only made a couple of adjustments. Traditionally, french onion soup is made with beef stock. I used chicken stock instead. Also, I didn’t cook the onions for forever and a day; 20 minutes was enough. Wish I could find a way around slicing them – my eyes are still burning. But, this is one of my favorite soups, so a bucket of tears is always worth it.
If time permits, and the baby takes a longer nap, I think I’m gonna go make this happen again today. Maybe I will ward off some germs and viruses…
Slow Cooker French Onion Soup
Prep time
Cook time
Total time
Serves: 4 to 6 servings
  • 4 tablespoons butter
  • 6 yellow onions, thinly sliced
  • ¼ teaspoon sugar
  • ½ teaspoon salt
  • ½ teaspoon black pepper
  • 6 cups beef broth or vegetable broth
  • ½ cup dry white wine
  • ½ teaspoon dry thyme
  • salt and pepper, to taste
  • sliced french bread
  • shredded gruyere cheese (if you can't find gruyere, use swiss cheese)
  1. Melt the butter in a large skillet, then add the sliced onions.
  2. Sautee until tender, about 5 minutes.
  3. Stir in the sugar, salt, and black pepper, and continue to sautee for 20 minutes, stirring occasionally.
  4. Transfer the onions to the slow cooker.
  5. Add broth, white wine, and thyme.
  6. Cook on low for 7 to 8 hours, or on high for 4 hours.
  7. Check for salt and pepper.
  8. Turn the oven-broiler on High.
  9. Ladle soup into ovenproof bowls.
  10. Top the bowls with a slice of french bread and cheese.
  11. Broil in oven until cheese is melted, 3 to 5 minutes.


  1. Audra says

    Just an idea…I am making the soup as I type! I used a vegetable slicer for the onions, no tears! Also another tip is breath through your mouth not your nose, it works! :-) thanks for the yummy recipe!

  2. says

    Hope your little one feels better soon! I had a sick household yesterday {hubby & both kids}, so I made them a big batch of tomato soup. French Onion is one of my favorites & this looks divine!!

  3. says

    Yup your granny is right , onions are full of vitamins C and I make tea for my kids when they are sick with onion..I know sounds disgusting but with some honey and lemon you could never tell it is with onions(w/peel). I hope your kiddos feel better soon! :*
    Your onion Soup looks fantastic, loving your presentation and recipe is tasty too!

  4. says

    I hope the little one is feeling better and that it’s not spreading around the house. :( Today is a day of coincidences I think. I’m catching up on blog reading tonight and the last post I read was also for French onion soup – which I’ve never had. And even more coincidental, I saw it on a menu this morning and decided I need to try it. I’m loving this slow cooker version – my kind of meal! :)

  5. Dan says

    This is a great idea that I’ve got to try. My brother once showed up with a scuba mask to chop onions. It seemed to work well for him.

  6. says

    My all time favorite soup….besides corn chowder….is French onion soup!!!! I love your recipe:-) My grandfather makes homemade onion soup that is truly to die for:-) I hope your babies are feeling better, Hugs, Terra

  7. says

    Oh! I hope your lumpy feels better soon :( That’s always a terrible thing to have to see.

    Do love this soup though! Winter is fast approaching in Cayman with temps dropping into GASP the 70s! Believe it or not, that totally calls for slow cookers. Bookmarking this bad boy!

  8. says

    I think I love your idea of changing the beef broth to chicken. I prefer chicken flavor and I will definitely give this recipe and cooking method a try. Onions are very healthy…. and I love them. :)

    I hope your sweet baby gets well quickly… I know it’s emotionally and physically tolling for parents when they are sick. My kids have coughs now and I wish I could magically get them better.

    Have a good weekend. ~ Ramona

  9. says

    My husband and I looooooooooooove French onion soup and we order it when it’s available. We’ve made once at home but it’s been a while. I don’t own a slow cooker but maybe I can cook slowly on a cast iron? Looks so delicious!


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