Slow Cooker French Onion Soup Recipe

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December 26, 2014

I ran across this recipe, courtesy of Melissa D’Arabian, at Food Network. I love onion soup so decided to try it myself. Since it is just my husband and I at home, I knew I would make a big batch and freeze the rest. The question was how to do it? I ended up buying tin foil soup containers at the grocery store and filled them with the soup. I froze those overnight, then placed a slice of bread and the cheese on top. I then placed the container in a food saver bag and used the food saver to remove all the air. Now whenever we want to eat the soup, we just pull a bowl out of the freezer, pop it in the oven and cook for about 40 minutes at 400 degrees. Delish!

French Onion Soup Recipe


For the caramelized onions:

  • 5 cups sliced yellow onions, (about 4 large onions)
  • 2 shallots, peeled and sliced
  • 1 clove garlic, minced
  • 1 tablespoon olive oil
  • Salt and ground black pepper

For the soup:

  • 1 teaspoon all-purpose flour
  • 1/4 cup dry sherry
  • 1 teaspoon dry thyme
  • Small sprig fresh rosemary
  • 1 teaspoon Worcestershire sauce
  • 2 cups low-sodium chicken broth
  • 2 cups low-sodium beef broth
  • 1 cup water
  • 1 tablespoon lemon juice
  • 6 thin slices baguette, toasted until golden and quite dry
  • 1/2 cup grated Gruyere cheese


  1. Coat a 4-quart or larger slow cooker with cooking spray.
  2. Add the onions, shallots, garlic and oil. Toss well, then season with a bit of salt and pepper.
  3. Cover and cook on low until the onions are richly colored and sweet, 8 to 10 hours or overnight. (The onions at this point can be removed and used for other recipes if not making the soup.)
  4. Once the onions are cooked, sprinkle with flour and stir until well-combined.
  5. Add the sherry, thyme, rosemary, Worcestershire sauce, both broths and the water.
  6. Cover and cook for another 4 hours on low or 2 hours on high.
  7. Once soup is done, stir in lemon juice and adjust the seasoning.
  8. When ready to eat, set the broiler on high. Ladle the soup into broiler-safe serving crocks.
  9. Top each crock with a thin slice of the toasted baguette and a heaping tablespoon of Gruyere.
  10. Place the filled crocks on a rimmed baking sheet and broil just until cheese is golden, 1 to 2 minutes. Do not leave the crocks unattended as they will burn quickly.

Both my husband and I thought there was too much of a rosemary flavor, so I added about a half a cup more of the chicken and beef broth.  I also added some onion powder for more of an onion flavor.


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