French Onion Soup

This French Onion Soup is so decadent and hearty, with a couple unique added twists! 
Course Appetizer, Main Course, Soup
Cuisine French
Keyword french onion soup, soup
Prep Time 15 minutes
Cook Time 2 hours 55 minutes
Total Time 3 hours 10 minutes
Servings 6 servings
Calories 612kcal
Author Dana at


For the soup

  • 1/2 cup unsalted butter
  • 4 large sweet onions sliced thin
  • 4 cloves garlic sliced thin
  • 4 dried bay leaves
  • 8 fresh thyme sprigs
  • 1 teaspoon kosher salt
  • 10 cracks fresh black pepper
  • 1 cup dry red wine I used chianti
  • 3 tablespooons all purpose flour heaping tablespoons
  • 2 quarts beef stock
  • 2 tablespoons balsamic vinegar

For the topping

  • 6 slices French bread
  • 6 tablespoons olive oil
  • 4 ounces gruyere cheese shredded


For the soup

  • In a large pot with a heavy bottom, I like to use a dutch oven, melt the butter over medium-low heat. Add the onions and garlic, stir to coat in the butter. Add the bay leaves, thyme, salt, and pepper. Stir to combine. Reduce the heat to low and cook for two hours, so the onions caramelize. Stir every 5 or so minutes so they do not burn. It is ready when the mixture is a medium golden brown color.
  • Add the wine and stir to combine, cook an additional 20-30 minutes stirring occasionally until the liquid is reduced by 3/4. The mixture will not become completely dry because of all of the butter, but we are cooking out the wine in this step. Discard the bay leaves and thyme.
  • Sprinkle the mixture with the flour and stir to combine. Let cook, stirring occasionally for 5 additional minutes so the raw flour taste cooks out of the mixture. Add the stock a little at a time at first and stir to combine, making sure there are no lumps. After one quart is added, stir to make sure there are no more lumps and add the remaining stock. Bring to a simmer, simmer 10 minutes. Taste, adjust seasoning if necessary.

For the topping

  • Turn on the broiler in the oven to the lowest setting. Brush the bread with the olive oil on both sides. Arrange the bread slices on a sheet tray and toast in the oven, flipping halfway through one you reach your desired toastiness. 
  • Remove sheet tray from the oven and crank the broiler to high. Evenly distribute the cheese among the bread slices. Broil cheese bread until your desired color on the cheese, do not burn! Serve with the soup, on the side for a more crunchy topping or floating on top of the soup for a more traditional style. 



Calories: 612kcal | Carbohydrates: 44g | Protein: 20g | Fat: 37g | Saturated Fat: 15g | Cholesterol: 61mg | Sodium: 1408mg | Potassium: 725mg | Fiber: 2g | Sugar: 4g | Vitamin A: 725IU | Vitamin C: 2.7mg | Calcium: 265mg | Iron: 3.7mg