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Homemade French Onion Soup with Cheesy Crouton Lids photo

French Onion Soup with Cheesy Crouton Lids

This French Onion Soup is SO comforting! Deeply caramelized onions meet rich beef broth, topped with cheesy, golden crouton lids for the ultimate cozy meal.
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Prep Time 20 minutes
Cook Time 1 hour
Total Time 1 hour 20 minutes
Servings: 4 servings
Course: Main Course, Soup
Cuisine: French
Ingredients Equipment Method Notes

Ingredients
  

Main Ingredients
  • 4 large Yellow onions
  • 4 tablespoons Unsalted butter
  • 1 tablespoon Olive oil
  • 1 teaspoon Sugar
  • 2 cloves Garlic minced
  • 8 cups Beef broth low-sodium
  • 1 teaspoon Dried thyme
  • 1 Bay leaf
  • Salt to taste
  • Freshly ground black pepper to taste
  • 8 slices Crusty bread sturdy baguette or sourdough
  • 1 cup Gruyère cheese shredded
  • 1 cup Mozzarella cheese shredded
  • Turkey bacon optional, cooked and crumbled for garnish

Equipment

  • Large heavy-bottomed pot or Dutch oven
  • Sharp chef’s knife
  • Wooden spoon or heatproof spatula
  • Soup bowls that can go under the broiler
  • Oven or broiler
  • Grater

Method
 

Preparation
  1. Peel and thinly slice 4 large yellow onions evenly using a sharp chef’s knife.
Caramelizing Onions and Making Soup
  1. In a large heavy-bottomed pot or Dutch oven, melt 4 tablespoons unsalted butter with 1 tablespoon olive oil over medium heat.
  2. Add the sliced onions and sprinkle 1 teaspoon sugar over them. Stir occasionally and cook low and slow for 40-50 minutes until onions are deep golden brown and tender.
  3. Stir in 2 cloves minced garlic and cook for 1 minute until fragrant.
  4. Pour in 8 cups low-sodium beef broth, add 1 teaspoon dried thyme and 1 bay leaf. Season with salt and freshly ground black pepper to taste.
  5. Bring to a gentle simmer, cover partially, and cook for 20-30 minutes to meld flavors.
Preparing Crouton Lids
  1. While soup simmers, toast 8 slices of crusty bread until golden.
  2. Combine 1 cup shredded Gruyère and 1 cup shredded mozzarella cheese. Pile cheese generously on each toasted bread slice.
  3. Preheat oven broiler. Place cheese-topped bread slices on a baking sheet and broil for 2-4 minutes until cheese bubbles and turns golden brown.
Serving
  1. Remove bay leaf from soup. Ladle hot soup into oven-safe bowls.
  2. Place a cheesy crouton lid on top of each bowl. Optionally, sprinkle cooked and crumbled turkey bacon over lids.
  3. Serve immediately and enjoy the melty, crispy, savory goodness!

Notes

  • Slowly caramelize onions over low heat to develop sweet, deep flavor without burning.
  • Toast bread slices before adding cheese to prevent sogginess and ensure a crunchy crust.
  • Use fresh shredded cheese instead of pre-shredded for better melting and texture.
  • Store soup separately from croutons; reheat soup and toast fresh bread with cheese before serving.
  • Substitute vegetable broth and omit turkey bacon for a vegetarian version.