Description
Classic French Onion Soup is a rich and comforting dish featuring deeply caramelized onions simmered in beef stock, deglazed with red wine, and finished with fresh thyme and balsamic vinegar. Topped with toasted crostinis and melted Gruyere cheese, this hearty soup is perfect for a cozy meal.
Ingredients
Soup Base
- 3 ounces unsalted butter
- 4 peeled and thickly sliced yellow onions
- 4 peeled and thickly sliced white onions
- 1 ½ tablespoons sugar
- 6 finely minced cloves of garlic
- 2 cups red wine
- 12 cups beef stock
- 2 tablespoons chopped fresh thyme
- 2 tablespoons balsamic vinegar
- sea salt and fresh cracked pepper to taste
Toppings
- 16 crostinis
- 4 cups shredded Gruyere cheese
Instructions
- Heat Butter: Melt the unsalted butter over low heat in a large pot to prepare for caramelizing the onions.
- Caramelize Onions: Add the peeled and thickly sliced yellow and white onions to the pot. Cook over low heat, stirring occasionally, allowing the onions to caramelize slowly for up to an hour until they are deeply golden and sweet.
- Add Sugar: Halfway through caramelization, sprinkle in the sugar to help the onions brown further and enhance their sweetness. This step ensures the onions develop a rich caramel flavor.
- Sweat Garlic: Once the onions are caramelized, add the finely minced garlic to the pot and cook gently for 3 to 4 minutes to soften and release its aroma without browning.
- Deglaze with Wine: Pour in the red wine and cook until the liquid is mostly absorbed by the onions, a process known as ‘au sec’, which intensifies the flavor.
- Simmer Soup: Add the beef stock to the pot and bring the soup to a gentle simmer. Allow it to cook for at least 20 minutes to meld the flavors.
- Season Soup: Stir in the chopped fresh thyme, season with sea salt and freshly cracked pepper to taste, and adjust the flavor by adding balsamic vinegar.
- Prepare Bowl Toppings: Pour the soup into oven-safe bowls. Top each bowl with several crostinis and sprinkle ½ to 1 cup of shredded Gruyere cheese over the top.
- Broil Cheese: Place the soup bowls on a sheet tray and cook under a high broiler for 3 to 4 minutes or until the cheese is melted, bubbly, and golden brown. Serve immediately.
Notes
- Caramelizing onions slowly over low heat is crucial for developing the rich, sweet flavor essential to this soup.
- Adding sugar is optional but helps if your onions lack natural sweetness.
- The choice of red wine should be a dry, full-bodied variety to complement the beef stock.
- Use fresh thyme for best flavor; dried thyme can be used but use about one-third the amount.
- The broiling step gives the soup its signature melted cheesy crust, so do not skip it.
- For a vegetarian version, substitute beef stock with vegetable stock and use a vegetarian-friendly cheese.
- Prep Time: 20 minutes
- Cook Time: 2 hours 10 minutes
- Category: Soup
- Method: Stovetop
- Cuisine: French
