Description
This classic French Onion Soup recipe is a rich and comforting dish featuring slowly caramelized onions simmered in a flavorful broth, topped with toasted French bread and melted Gruyere, Mozzarella, and Parmesan cheeses. Perfect as a starter or a hearty meal, it combines sweetness from the onions with a savory, cheesy crust that’s broiled to golden perfection.
Ingredients
Scale
Soup Base
- 4 tablespoons unsalted butter
- 5 large yellow onions, thinly sliced
- 1 teaspoon salt
- 1 teaspoon granulated sugar
- 2 cloves garlic, minced
- 1/2 cup dry red wine (such as Merlot or Pinot Noir)
- 32 ounces low-sodium beef broth
- 24 ounces low-sodium chicken broth
- 1 tablespoon Worcestershire sauce
- 2 sprigs fresh thyme
- 1 bay leaf
- 1/2 tablespoon balsamic vinegar
- Pinch of salt and freshly ground black pepper, to taste
Bread and Cheese Topping
- 5 slices French bread, 1-inch thick
- 2 tablespoons olive oil
- 1 1/2 cups shredded Gruyere Swiss cheese, room temperature
- 1/4 cup shredded Mozzarella cheese, room temperature
- 2 tablespoons finely grated Parmesan cheese, room temperature
Instructions
- Caramelize the Onions: In a large pot over medium-high heat, melt the butter. Add the thinly sliced onions and sauté, stirring frequently, until softened, about 10 minutes. Reduce heat to medium and stir in the salt and sugar. Continue cooking for another 35 minutes, stirring occasionally every 5 minutes or so, until the onions are deeply caramelized and syrupy.
- Add Garlic and Deglaze: Stir in the minced garlic and cook for about 20 seconds until fragrant. Pour in the dry red wine to deglaze the pot, scraping up any brown bits from the bottom and sides to incorporate the flavor into the soup.
- Add Broth and Herbs: Add the beef broth, chicken broth, Worcestershire sauce, fresh thyme sprigs, and bay leaf to the pot. Gently simmer over medium to medium-low heat for about 20 minutes, stirring occasionally to meld the flavors.
- Season and Keep Hot: Remove and discard the thyme sprigs and bay leaf. Stir in the balsamic vinegar and taste the soup. Season with additional salt and freshly ground black pepper as needed. Reduce heat to low and cover to keep soup warm while preparing the bread.
- Prepare the Toasted Bread: Preheat the oven broiler with the rack positioned about 6 inches from the heat source. Arrange the French bread slices on a baking sheet and brush both sides with olive oil. Broil the bread for 2-3 minutes total, flipping once halfway through, until well toasted and golden. Watch carefully to avoid burning as broilers vary in intensity.
- Assemble the Soup Bowls: Place oven-safe bowls or crocks on a rimmed baking sheet. Fill each bowl about two-thirds full with the hot soup. Top each bowl with one slice of toasted bread and evenly sprinkle with the Gruyere, Mozzarella, and Parmesan cheeses.
- Broil the Topped Soup: Return the baking sheet with bowls to the broiler. Broil until the cheese is bubbly and golden brown, melting over the edges to form a deliciously crusty seal. Keep a close eye to prevent burning.
- Serve and Enjoy: Carefully remove the baking sheet from the oven. Serve the French Onion Soup hot and enjoy the rich, savory flavors and gooey cheesy topping.
Notes
- To make this soup vegetarian, use vegetable broth instead of beef and chicken broth and substitute with vegan Worcestershire sauce; note this will alter the depth of flavor.
- If avoiding alcohol or wine, omit the red wine and replace it with extra broth, though the soup won’t have as rich a flavor.
- If you don’t have oven-safe bowls for broiling, you can omit the broil step: make cheese toasts separately on a baking sheet and add them to the soup before serving or simply use croutons.
Nutrition
- Serving Size: 1 bowl (approximately 350 grams)
- Calories: 350
- Sugar: 8g
- Sodium: 700mg
- Fat: 15g
- Saturated Fat: 8g
- Unsaturated Fat: 6g
- Trans Fat: 0g
- Carbohydrates: 40g
- Fiber: 3g
- Protein: 18g
- Cholesterol: 45mg
