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Crockpot French Onion Soup Recipe
Ash Tyrrell

Crockpot French Onion Soup Recipe

I’ve always loved the comforting flavor of French Onion Soup, but the traditional stovetop version felt like a lot of work. Then I tried making it in a crockpot—and wow, it changed everything!
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Prep Time 20 minutes
Cook Time 8 hours
Servings: 6
Ingredients Method Notes

Ingredients
  

  • 5 –6 medium yellow onions thinly sliced – Yellow onions are naturally sweet and perfect for caramelizing. Don’t use red; they can turn bitter.
  • 4 tablespoons unsalted butter – Helps caramelize the onions slowly and evenly.
  • 2 tablespoons olive oil – Prevents the butter from burning and adds richness.
  • 4 garlic cloves minced – Fresh garlic adds a delicious savory depth.
  • 8 cups beef broth – I went with low-sodium so I could better control the salt.
  • ½ cup dry white wine – Optional but it brings out incredible flavor and aroma.
  • 2 tablespoons Worcestershire sauce – Adds umami and complexity.
  • 1 teaspoon sugar – Speeds up caramelization and enhances sweetness.
  • 1 teaspoon dried thyme – Gives the soup a warm earthy note.
  • Salt and black pepper to taste – Adjust according to your preference.
  • Baguette slices toasted – These act as the cheesy lid that soaks up all that goodness.
  • 1 ½ cups Gruyère cheese shredded – Grate it fresh if you can; it melts better and tastes sharper.

Method
 

  1. First things first—slice your onions thin. Heat butter and olive oil in a large skillet over medium heat. Add the onions and sprinkle in the sugar. Stir every few minutes for about 25–30 minutes, until the onions are deeply golden and fragrant. Don’t rush this step—it’s where all that rich flavor starts.
  2. Once the onions are ready, pour them into your crockpot. Add the minced garlic, beef broth, white wine (if using), Worcestershire sauce, and thyme. Season with salt and pepper. Give everything a good stir so the flavors begin to mingle.
  3. Cover your crockpot and set it on low for 6–8 hours or high for 4 hours. You’ll know it’s ready when your kitchen smells amazing and the onions have practically melted into the broth.
  4. As the soup finishes cooking, preheat your oven and toast the baguette slices until golden and crisp. This makes sure they hold up under the cheese and soup instead of going soggy.
  5. Ladle hot soup into oven-safe bowls. Place a toasted baguette slice on each and pile on the shredded cheese. Broil for 1–2 minutes until the cheese is melted, bubbly, and slightly golden on top.
  6. Carefully remove the bowls from the oven—they’ll be hot! Serve immediately and enjoy every cheesy, savory spoonful. A simple green salad makes a perfect side.

Notes

  • Always caramelize the onions slowly—don't crank up the heat.
  • Grate cheese fresh from a block. It melts way better than pre-shredded.
  • Don’t skip the sugar when caramelizing; it makes a big difference.
  • Add a splash of balsamic vinegar for a tangy depth (try it once—you’ll thank me).
  • Make it ahead and reheat—it tastes even better the next day!