French Onion Casserole
French Onion Casserole
Ingredients
For the French Onion Base
- 4 yellow onions, large, thinly sliced (about 3 pounds)
- 4 tablespoons unsalted butter
- 1 tablespoon olive oil
- 1 teaspoon granulated sugar, optional
- 1 teaspoon salt, plus more to taste
- 1/2 teaspoon black pepper, freshly ground, plus more to taste
- 2 garlic, cloves, minced
- 1/4 cup all-purpose flour
- 1 cup dry red wine, such as Merlot or Cabernet Sauvignon, or dry sherry
- 6 cups beef broth, preferably low-sodium and good quality
- 1 tablespoon Worcestershire sauce
- 1 teaspoon fresh thyme leaves, or 1/2 teaspoon dried thyme
- 1 bay leaf
For Assembly and Garnish
- 6 sturdy bread, slices (such as baguette or sourdough), about 1-inch thick, toasted or grilled
- 8 ounces Gruyere cheese, shredded (or a blend of Gruyere and Mozzarella)
- 2 tablespoons fresh parsley, chopped, for garnish (optional)
Instructions
- 1
Peel and thinly slice the 4 large yellow onions. For even cooking, try to slice them uniformly.
⏱️ 10 min
- 2
In a large Dutch oven or heavy-bottomed pot, melt 4 tablespoons of unsalted butter with 1 tablespoon of olive oil over medium-low heat. Add the sliced onions, 1 teaspoon of granulated sugar (if using), 1 teaspoon of salt, and 1/2 teaspoon of freshly ground black pepper. Stir well to coat the onions.
⏱️ 5 min
- 3
Cook the onions slowly, stirring occasionally (every 10-15 minutes), for 45 minutes to 1 hour, or until they are deeply caramelized and a rich golden-brown color. This step is crucial for flavor development. Scrape any browned bits from the bottom of the pot as you stir.
⏱️ 50 min
- 4
Add 2 cloves of minced garlic to the caramelized onions and cook for another 1-2 minutes until fragrant.
⏱️ 2 min
- 5
Sprinkle 1/4 cup of all-purpose flour over the onions and stir constantly for 2-3 minutes to cook out the raw flour taste, creating a roux.
⏱️ 3 min
- 6
Pour in 1 cup of dry red wine (or dry sherry). Scrape the bottom of the pot vigorously with a wooden spoon to release any remaining flavorful browned bits (fond). Simmer for 5-7 minutes until the liquid has mostly evaporated and thickened slightly.
⏱️ 6 min
- 7
Gradually whisk in 6 cups of beef broth. Add 1 tablespoon of Worcestershire sauce, 1 teaspoon of fresh thyme leaves, and 1 bay leaf. Bring the mixture to a simmer.
⏱️ 5 min
- 8
Reduce the heat to low, cover, and simmer for at least 20-30 minutes, allowing the flavors to meld. Taste and adjust seasoning with additional salt and pepper if needed. Remove the bay leaf before proceeding.
⏱️ 25 min
- 9
Preheat your oven to 375°F. Lightly grease a 9x13 inch baking dish or individual oven-safe crocks.
⏱️ 5 min•🌡️ 375
- 10
Pour the French onion soup base into the prepared baking dish. Arrange the 6 slices of toasted or grilled bread over the top of the soup, ensuring they are partially submerged.
⏱️ 5 min
- 11
Evenly sprinkle 8 ounces of shredded Gruyere cheese over the bread slices, covering them completely.
⏱️ 2 min
- 12
Bake for 20-25 minutes, or until the cheese is melted, bubbly, and golden-brown. For a deeper golden crust, you can briefly broil it for the last 1-2 minutes, watching carefully to prevent burning.
⏱️ 22 min•🌡️ 375
- 13
Remove from the oven and let the casserole rest for 5-10 minutes before serving. This allows the liquid to settle and prevents burns. Garnish with 2 tablespoons of chopped fresh parsley, if desired.
⏱️ 10 min
Kitchen Tools
French Onion Casserole
For the French Onion Base
- 4 yellow onions, large, thinly sliced (about 3 pounds)
- 4 tablespoons unsalted butter
- 1 tablespoon olive oil
- 1 teaspoon granulated sugar, optional
- 1 teaspoon salt, plus more to taste
- 1/2 teaspoon black pepper, freshly ground, plus more to taste
- 2 garlic, cloves, minced
- 1/4 cup all-purpose flour
- 1 cup dry red wine, such as Merlot or Cabernet Sauvignon, or dry sherry
- 6 cups beef broth, preferably low-sodium and good quality
- 1 tablespoon Worcestershire sauce
- 1 teaspoon fresh thyme leaves, or 1/2 teaspoon dried thyme
- 1 bay leaf
For Assembly and Garnish
- 6 sturdy bread, slices (such as baguette or sourdough), about 1-inch thick, toasted or grilled
- 8 ounces Gruyere cheese, shredded (or a blend of Gruyere and Mozzarella)
- 2 tablespoons fresh parsley, chopped, for garnish (optional)
Instructions
- 1
Peel and thinly slice the 4 large yellow onions. For even cooking, try to slice them uniformly.
⏱️ 10 min - 2
In a large Dutch oven or heavy-bottomed pot, melt 4 tablespoons of unsalted butter with 1 tablespoon of olive oil over medium-low heat. Add the sliced onions, 1 teaspoon of granulated sugar (if using), 1 teaspoon of salt, and 1/2 teaspoon of freshly ground black pepper. Stir well to coat the onions.
⏱️ 5 min - 3
Cook the onions slowly, stirring occasionally (every 10-15 minutes), for 45 minutes to 1 hour, or until they are deeply caramelized and a rich golden-brown color. This step is crucial for flavor development. Scrape any browned bits from the bottom of the pot as you stir.
⏱️ 50 min - 4
Add 2 cloves of minced garlic to the caramelized onions and cook for another 1-2 minutes until fragrant.
⏱️ 2 min - 5
Sprinkle 1/4 cup of all-purpose flour over the onions and stir constantly for 2-3 minutes to cook out the raw flour taste, creating a roux.
⏱️ 3 min - 6
Pour in 1 cup of dry red wine (or dry sherry). Scrape the bottom of the pot vigorously with a wooden spoon to release any remaining flavorful browned bits (fond). Simmer for 5-7 minutes until the liquid has mostly evaporated and thickened slightly.
⏱️ 6 min - 7
Gradually whisk in 6 cups of beef broth. Add 1 tablespoon of Worcestershire sauce, 1 teaspoon of fresh thyme leaves, and 1 bay leaf. Bring the mixture to a simmer.
⏱️ 5 min - 8
Reduce the heat to low, cover, and simmer for at least 20-30 minutes, allowing the flavors to meld. Taste and adjust seasoning with additional salt and pepper if needed. Remove the bay leaf before proceeding.
⏱️ 25 min - 9
Preheat your oven to 375°F. Lightly grease a 9x13 inch baking dish or individual oven-safe crocks.
⏱️ 5 min•🌡️ 375 - 10
Pour the French onion soup base into the prepared baking dish. Arrange the 6 slices of toasted or grilled bread over the top of the soup, ensuring they are partially submerged.
⏱️ 5 min - 11
Evenly sprinkle 8 ounces of shredded Gruyere cheese over the bread slices, covering them completely.
⏱️ 2 min - 12
Bake for 20-25 minutes, or until the cheese is melted, bubbly, and golden-brown. For a deeper golden crust, you can briefly broil it for the last 1-2 minutes, watching carefully to prevent burning.
⏱️ 22 min•🌡️ 375 - 13
Remove from the oven and let the casserole rest for 5-10 minutes before serving. This allows the liquid to settle and prevents burns. Garnish with 2 tablespoons of chopped fresh parsley, if desired.
⏱️ 10 min