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French Onion Soup

This French Onion Soup brings deeply caramelized onions, rich broth, toasted baguette slices, and perfectly melted Gruyere together into a warm, soul-soothing classic—made without alcohol but still packed with incredible depth.
Prep Time15 minutes
Cook Time1 hour
Total Time1 hour 15 minutes
Servings: 6

Ingredients

  • 4 large yellow onions thinly sliced
  • 2 large sweet onions thinly sliced
  • 6 tablespoons butter
  • 2 sprigs fresh thyme
  • 2 bay leaves
  • 3/4 cup mixture of beef broth + 1 teaspoon lemon juice alcohol-free substitute for white wine
  • 4 cups high-quality beef broth
  • 1.5 cups chicken broth
  • Salt to taste
  • Pepper to taste
  • 1 baguette sliced
  • 3 tablespoons olive oil optional, for brushing bread
  • 6 slices Gruyere cheese

Instructions

  • Slice all onions thinly and set aside.
  • Melt butter in a large pot over medium heat.
  • Add all onions and cook, stirring occasionally, for 30–35 minutes until deeply caramelized.
  • Add thyme and bay leaves and stir to combine.
  • Deglaze with broth + lemon juice mixture, scraping browned bits from the pot.
  • Add beef broth and chicken broth and stir well.
  • Season with salt and pepper to taste.
  • Bring soup to a gentle simmer.
  • Cover partially and cook 20–25 minutes.
  • Meanwhile, preheat the oven broiler.
  • Arrange baguette slices on a baking sheet.
  • Brush with olive oil if desired.
  • Broil 2–3 minutes until lightly toasted.
  • Ladle hot soup into oven-safe bowls.
  • Top each bowl with a toasted baguette slice.
  • Place a slice of Gruyere on top of each serving.
  • Broil bowls 2–4 minutes until cheese is melted and bubbling.
  • Serve immediately while hot and gooey.

Notes

Ingredient Substitutions

  • Swap Gruyere with Swiss or provolone.
  • Use all beef broth if you prefer a stronger flavor.
  • Replace lemon juice with apple cider vinegar for a different brightness.

Make-Ahead & Storage

  • Store soup (without bread and cheese) up to 4 days in the fridge.
  • Freeze the soup base for up to 3 months.
  • Broil cheese topping fresh for best texture.

Serving Variations

  • Add extra baguette slices for a thicker cheesy “lid.”
  • Add caramelized mushrooms for more umami.
  • Serve with roasted chicken or salad for a full meal.

Avoid Common Mistakes

  • Don’t rush caramelizing onions — slow cooking is essential.
  • Avoid burning the onions; adjust heat if they darken too fast.
  • Use high-quality broth for deeper flavor.