![French Onion Soup](https://cdn.statically.io/img/www.foodandwine.com/thmb/rzwys_PvzUvNtChNJewwVO6NFYY=/1500x0/filters:no_upscale():max_bytes(150000):strip_icc()/201504-xl-french-onion-soup-b6d0295ec68d4d0e839e2f30e4ea2ab2.jpg)
Ingredients
BEEF BROTH
-
5 pounds beef neck and shinbones
-
2 onions, halved
-
2 leeks, white and light green parts only, chopped
-
1 carrot, chopped
-
1 head of garlic, halved
-
3 thyme sprigs
-
6 parsley sprigs
-
2 bay leaves
-
1/2 teaspoon whole black peppercorns
SOUP
-
2 tablespoons canola oil
-
8 large onions (4 pounds), thinly sliced
-
Kosher salt
-
2 tablespoons unsalted butter
-
2 tablespoons all-purpose flour
-
3 1/2 quarts beef broth (above)
-
Bouquet garni made with 2 bay leaves, 4 thyme sprigs and 1 teaspoon whole black peppercorns
-
1 tablespoon Cognac
-
2 tablespoons apple cider vinegar
-
Pepper
FOR SERVING
-
Toasted baguette slices
-
4 ounces cave-aged Gruyère, shredded (1 1/2 cups)
-
4 ounces Emmental cheese, shredded (1 1/2 cups)
-
Chopped chives
-
Black pepper
Directions
Make the beef broth
-
Preheat the oven to 450°. Arrange the bones on a baking sheet and roast for about 30 minutes, until browned. Transfer to a very large pot and add all of the remaining ingredients. Add 7 quarts of water and bring to a boil. Cook over moderately high heat, skimming as necessary, until reduced by half (to 3 1/2 quarts), about 1 hour. Strain the broth into a large bowl and skim off the fat.
Meanwhile, start the soup
-
In a large pot, heat the oil. Add the onions and cook over moderately low heat, stirring frequently, until deep golden, about 1 hour. Season with salt.
-
Stir the butter into the onions until melted. Add the flour and cook over moderate heat, stirring, until the flour is incorporated and the onions are sizzling, 2 to 3 minutes. Add the beef broth and bouquet garni and bring to a simmer. Cook until reduced to 10 cups, about 35 minutes. Discard the bouquet garni. Stir in the Cognac and vinegar and season the soup with salt and pepper.
-
Preheat the broiler. Ladle the soup into 6 ovenproof bowls set on a baking sheet. Top with toasted baguette slices. Toss the cheeses together and sprinkle over the bread. Broil 6 inches from the heat for 7 to 8 minutes, until the cheese is melted and golden. Garnish with chives and pepper and serve.
Make Ahead
The broth and caramelized onions can be made 2 days ahead and refrigerated separately. Remove all of the fat from the beef broth before making the soup.