French Onion Soup

Serves 4 to 8

INGREDIENTS

• 3 pounds (1.4 kg) small to medium yellow onions
• 4 tablespoons (55 g) unsalted European-style butter
• Large pinch fleur de sel, plus more for seasoning
• 3 tablespoons all-purpose flour
• 1⁄4 cup (60 ml) dry white wine, such as Burgundy Chardonnay
• 3 quarts (2.8 L) beef stock, homemade preferred
• 1 bouquet garni
• 2 pounds (910 g) Comté cheese, half grated, half cut into 1⁄4-inch (6-mm) slices
• 8 to 12 toasted baguette slices

Cut off the root end and top of each onion. Peel the onions and halve them lengthwise, then slice each half lengthwise following the lines of the onion into thin (1⁄4-inch / 6-mm) slices.

In a 7-quart (6.6-L) or similar-size Dutch oven or heavy pot, melt the butter over medium heat. Add the sliced onions and salt. Reduce the heat to the lowest setting and cook very slowly, occasionally stirring with a wooden spoon to make sure the onions aren’t burning, until the onions are caramelized to a deep golden brown, 1 to 11⁄2 hours. You want to cook them slowly to bring out their inner sweetness and let the moisture evaporate, but you do not want to burn them.

Add the flour to the onions and cook for 5 minutes, stirring. Add the white wine and let simmer for 1 to 2 minutes, stirring to scrape any browned bits off the bottom of the pan. Add the beef stock and bouquet garni and bring to a simmer. Simmer the soup, stirring occasionally, until thickened slightly, 6 to 8 minutes. Remove the bouquet garni and season with salt. (You can make the soup to this point, cool to room temperature, and refrigerate up to 3 days before serving. Bring the soup back to a simmer before continuing.)

Preheat the broiler to high. Position a rack in the middle of the oven. Arrange 4 to 8 heatproof bowls (whose capacity adds up to about 12 cups) on a sturdy 13 by 18-inch (33 by 46-cm) sheet pan.

Add a big pinch of grated cheese to the bottom of each bowl. Fill the soup bowls with soup, leaving about 1⁄2 inch (12 mm) at the top for the bread and cheese. Divide half the remaining grated cheese among the bowls, top with the toasted baguette slices, then add the rest of the grated cheese. Broil in the oven until the cheese is melted and bubbling, checking frequently to make sure the toasts don’t get too brown, 1 to 3 minutes. Remove and add the slices of Comté and place in the oven to broil for another 1 to 3 minutes, until melted, bubbling, and just beginning to brown. Serve immediately.

Allow any leftover soup to cool to room temperature, then transfer to a sealed container and refrigerate up to 3 days. Reheat fully before serving and assembling as directed.