Slow Cooker French Onion Soup

Total Time
Prep 1 hr
Cook 4 hrs

I made this fantastic recipe for a big batch of onion soup that You can freeze in portions to use later. Serve this with a lovely red wine and salad and voilà for a romantic meal. These are 14 large servings so if you are serving this before a meal reduce the amount of soup in your bowl.

Ingredients Nutrition


  1. Over medium heat sauté the onion in butter until soft and translucent and caramel colour. Make this in 3 batches.
  2. Place onions in slow cooker.
  3. Deglaze cooking skillet with some of the beef stock;this is the secret to that taste.
  4. Add to slow cooker along with the remaining beef broth (your own homemade or powdered mixed with boiling water).
  5. Add Worcestershire sauce, thyme and bay leaf.
  6. Cover; cook on High for 4 hours or on low for 6-8 hours.
  7. Add salt and pepper to taste. Remove bay leaf.
  8. Divide soup into appropriate containers.
  9. Seal and freeze.
  10. When ready to enjoy your French Onion Soup.
  11. Remove from freezer and place in a microwave dish with 2 tbsp sherry; heat for 5 minutes.
  12. Add Parmesan cheese to your onion soup bowl. Place one slice of toasted bread over the cheese. Fill bowl with soup.
  13. Top with shredded Gruyère cheese.
  14. Place under broiler to melt your cheese.
  15. Tip: When adding your ingredients to the slow cooker make sure they are all hot.
  16. Use the processor to slice your onions. I once read 'If I use my food processor just to make onion soup it will be worth the cost".
  17. Bon Appettit!


Most Helpful

This is perfect as written. Made the full recipe (just fit in a 6 qt. slow cooker) and I'll be lucky if I get to freeze half. ;) Been looking for the perfect FO soup recipe and now I've found it - a plus being less complicated than others I've tried - thanks!

DeniseMB August 14, 2012

Easy to make ... not too much fuss and tasted great, but mostly I Loved that it was not overly salty as many French Onion Soups are. I added quite a bit of pepper at the end to deepen the flavor though.

annabella873 February 16, 2012

Loved this recipe. I pared it down a little bit--just four pounds of onions and about ten cups of broth.

Just before serving it, I dished it out into ramekins. Then I sliced the French bread, laid a slice on top of the soup, but partially sticking out of the bowl too. I sprinkled mozzarella cheese over top (didn't have any other variety at the moment) and broiled it for about 3 minutes. Turned out perfect!

Joellen1972 December 12, 2011

Join the Conversation

  • all
  • reviews
  • tweaks
  • q & a