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Entirely Made in the Slow Cooker French Onion Soup

Course Main
Author Maggie @ The Love Nerds


  • 4 large onions sliced pole to pole
  • 6 tbsp butter salted and melted
  • 10 c beef broth
  • 1/4 c Balsamic Vinaigrette
  • 1 tbsp Worcestershire sauce
  • 1 tsp pepper
  • 1 bay leaf
  • Slices of French bread 1 inch thick
  • Mozzarella cheese


  1. Mix onions and melted butter in the slow cooker.
  2. Cover and cook on low for 10-12 hours overnight or on high for 5-6 hours. I have not had an issue with these burning but I do give them a quick stir right before I go to bed and one more if I am up in the middle of the night.
  3. Add broth, Balsamic, pepper and Worcestershire sauce and stir. Add bay lead on top and cover and cook on low heat setting 7-9 hours (or on high heat setting 3-4 hours)
  4. To prepare Cheesy French Bread topping, place slices of bread on pan and top with a little bit of cheese. Broil for a couple minutes (keep a close eyes on them) and then add one to each bowl of soup. Serve immediately.