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The Best French Onion Soup
Main Dishes, Soup, Soups

The Ultimate French Onion Soup Recipe

French Onion Soup is without a doubt one of the most comforting and delicious soups out there. A rich broth layered with tons of caramelized onions and topped with crusty bread and cheese--What could be better?
If you've ever wanted to make restaurant-quality French Onion Soup from scratch, this is your recipe.
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Prep Time: 3 hours
Cook Time: 1 hour
Total Time: 4 hours
Makes: 6 - 8 servings

Ingredients

Beef Stock

  • 2 1/2 lbs beef finger ribs
  • 1/2 onion, chopped
  • 2 large carrots, chopped
  • 2 celery ribs, chopped
  • 4 garlic cloves, smashed
  • 2 fresh bay leaves
  • 20 cups water

French Onion Soup

  • 4 tablespoons unsalted butter
  • 3 white onions
  • 3 yellow onions*
  • 3 garlic cloves, thinly sliced
  • 2 fresh bay leaves
  • 1 tablespoon fresh thyme leaves
  • 2 teaspoons dijon mustard
  • 1 tablespoon Worcestershire sauce
  • 2/3 cup dry vermouth*
  • 8 cups beef stock
  • kosher salt
  • freshly cracked black pepper

Bread Topper

  • 1/2 french baguette, sliced 1 inch thick
  • 3 tablespoons softened butter
  • 1 garlic clove
  • 1 1/2 cups shredded gruyere cheese

Instructions

Beef Stock

  • Roast the bones. Line a baking sheet with foil and place the ribs side by side. Arrange an oven rack in the top 1/3 of the oven. Place the ribs under the broiler for 12-15 minutes, flipping halfway through until browned.
  • Make the stock. Add the roasted beef bones and any juices to a stock pot (8 qt+). Add the onion, carrot, celery, bay leaves, smashed garlic, and 20 cups of water. Bring to a simmer and skim any foam off that rises to the top. Simmer until reduced by just over half. You should end up with 8-10 cups of broth. Strain the broth through a mesh strainer into a mason jars or deli cups and discard the veggies and bones.

French Onion Soup

  • Slice the onions. Use a mandoline to ensure evenly sliced onions. Peel the onions then slice into 2mm thick slices. Set aside.
  • Caramelize the onions. Add the butter to a large dutch oven over medium heat. Once the butter is melted and foamy, add the onions and toss well to coat in the butter. Cover the pot and cook for 5 minutes. Uncover and reduce the heat to medium-low and season lightly with salt and pepper. Add the sliced garlic and bay leaves and toss well. Cook, stirring every 5-10 minutes, until the onions are deeply golden brown, about 45 min to 1 hour.
  • Season the onions. Once the onions are deeply browned, increase the heat to medium and add the dijon, Worcestershire, and thyme leaves to the pot. Once the onions are sizzling, add the vermouth and simmer for 5 minutes.
  • Make the soup. Add the beef stock to the onions and bring to a simmer. Simmer for 15-20 minutes, until slightly thickened. Season to taste with salt and pepper.
  • Preheat an oven to 425 F.
  • Toast the bread. Spread the baguette slices out on a baking sheet and spread with the softened butter and season with salt and pepper. Toast for 7-10 minutes, until golden brown. Once the bread is out of the oven, rub the toasted bread with a clove of garlic.
  • Broil. Ladle the soup into oven-safe bowls and top with the toasted baguette. Top with shredded gruyere and place the bowls on a baking sheet. Transfer to the oven for 10 minutes, finishing by broiling if needed.

Notes

*Do not use sweet or vidalia onions here, the soup ends up being too sweet. TRUST ME, I know.
*Dry vermouth has a specific flavor that I love here, but you could swap in dry white wine, if needed. 
  • TO STORE: Refrigerate soup in an airtight storage container for up to 1 week. Store bread separately in an airtight storage container at room temperature.
  • TO REHEAT: Rewarm leftovers in a pot on the stovetop over medium-low heat or in the microwave. If desired, toast leftover bread on a baking sheet in the oven at 350 degrees.
  • TO FREEZE: Freeze soup in an airtight, freezer-safe storage container for up to 3 months. Let thaw overnight in the refrigerator before reheating.

Nutrition

Calories: 422kcalCarbohydrates: 27gProtein: 20gFat: 25gSaturated Fat: 15gPolyunsaturated Fat: 1gMonounsaturated Fat: 7gTrans Fat: 1gCholesterol: 71mgSodium: 1104mgPotassium: 850mgFiber: 3gSugar: 8gVitamin A: 784IUVitamin C: 11mgCalcium: 423mgIron: 2mg