Description
This classic French Onion Soup recipe features slowly caramelized onions simmered in a rich beef broth, topped with toasted crusty French bread and melted Gruyere and mozzarella cheeses. Perfect as a comforting appetizer or a hearty meal, this soup combines deep, sweet onion flavors with a cheesy, golden crust.
Ingredients
Scale
Soup Base
- 1 tablespoon olive oil
- 3 pounds onions (about 5 or 6 medium sweet onions such as Maui or Vidalia)
- 2 tablespoons light brown sugar
- 1 1/2 teaspoons Worcestershire sauce
- 2 cloves garlic, minced
- 1 tablespoon butter (optional)
- 2 tablespoons all-purpose flour (optional)
- 1 cup wine (sherry, marsala, or port are good choices, optional)
- 8 cups beef stock (chicken or vegetable stock can be substituted)
- 1 small bunch fresh thyme
- 1 bay leaf
- 1 tablespoon kosher salt (or to taste)
- 1/4 teaspoon black pepper
Toppings
- 16 slices crusty French bread, toasted
- 1 cup shredded Gruyere cheese
- 1 cup shredded mozzarella cheese
Instructions
- Heat the olive oil: In a large, heavy-bottomed pot over medium heat, warm the olive oil to prepare for caramelizing the onions.
- Prepare and cook onions: Halve, peel, and thinly slice the onions. Add them to the pot and stir to coat them with oil.
- Caramelize onions: Add the brown sugar and Worcestershire sauce to the onions. Cook, stirring every few minutes, until the onions develop a deep golden brown color, which may take some time as this step is key to developing rich flavor.
- Add garlic: Stir in the minced garlic and cook until fragrant, about a minute, to enhance the soup’s aroma.
- Create roux (optional): Add butter to the pot and sprinkle in the flour. Stir continuously to combine, cooking briefly to remove raw flour taste. This helps thicken the soup slightly.
- Deglaze with wine (optional): Pour in the wine and stir well, scraping any flavorful browned bits stuck to the pot’s bottom. This adds depth to the broth.
- Add stock and herbs: Stir in the beef stock, add the thyme stems and bay leaf, then bring the soup to a gentle simmer.
- Season: Add kosher salt and black pepper to taste, adjusting seasoning as needed.
- Prepare for serving: Remove the thyme stems and bay leaf from the soup. Ladle the hot soup into heat-safe bowls or crocks.
- Add bread and cheese topping: Top each bowl with toasted French bread slices, then sprinkle evenly with shredded Gruyere and mozzarella cheese.
- Broil the topping: Place the bowls under a broiler until the cheese melts and is bubbly and browned, creating a delicious, savory crust.
- Serve: Carefully remove from the broiler and serve immediately to enjoy the rich flavors and melted cheese topping.
Notes
- I like to use a sweet onion variety such as Maui or Vidalia, but you can use any kind of onion you prefer.
- Using butter and flour to make a roux is optional but adds thickness to the soup.
- You can substitute beef stock with chicken or vegetable stock for a lighter or vegetarian-friendly version.
- For wine, sherry, marsala, or port provide a nice flavor, but you can omit if preferred.
- To toast the bread, use a toaster or oven oven broiler until golden for best results.
Nutrition
- Serving Size: 1 bowl (about 1 cup soup with bread and cheese)
- Calories: 320
- Sugar: 7g
- Sodium: 850mg
- Fat: 14g
- Saturated Fat: 7g
- Unsaturated Fat: 6g
- Trans Fat: 0g
- Carbohydrates: 28g
- Fiber: 3g
- Protein: 15g
- Cholesterol: 35mg
