Hot and cheesy French onion soup is a wintertime classic and a foolproof cure for those chilly days. Few things are more comforting and the ingredients are so basic it’s one of those things you can usually whip up at a moment’s notice even with the barest of refrigerator. For me, one of the best parts is also the one chance in the year to eat out of my cute soup crocks which I really only take out for this soup…just wouldn’t taste the same without them!
The key with making a fine French onion soup is long, slow cooking to allow the flavors to really develop, so don’t be in a rush. Caramelizing the onions will bring out their natural sweetness and your house will be filled with a transcendent aroma as a reward for your patience. The traditional cheese for this soup is Gruyere but feel free to experiment with other melting kinds such as Swiss, cheddar, etc. Served with a classic red wine and a side salad this is one of winter’s best simple supper.
Onion Soup Gratinée
Recipe adapted from Cooking at Home with the Culinary Institute of America
Active time: 1h30 min
Total time: 2h45 min
Makes 6 servings
¼ cup olive oil or vegetable oil
4 yellow onions, thinly sliced
2 cloves garlic, minced
½ cup brandy
6 cups beef or chicken broth, heated
1 spice sachet, including 1 sprig fresh tarragon or ½ teaspoon dried
Salt and freshly ground pepper
Eight ¼-inch-thick slices French bread
1½ cup shredded Gruyère cheese, or as needed
8 cups boiling water, or as needed
Heat the oil in a soup pot over medium-low heat. Add the onions and cook without stirring until they begin to brown on the bottom. Raise the heat to medium, stir, and continue to cook, stirring occasionally, until the onions are deeply caramelized, a dark golden brown, and very soft. The total cooking time will be 30-45 minutes. If the onions begin to scorch, add a few tablespoons of water.
Add the garlic and continue to cook for an additional minute. Add the brandy and stir to deglaze the pan, scraping up any browned bits from the pan bottom. Simmer until the liquid has nearly evaporated, 2-3 minutes.
Add the broth and sachet. Bring to a simmer and cook, partially covered, for 45-60 minutes, skimming foam from the surface as needed. Remove and discard the sachet. Taste and season with salt and pepper.
At this point, the soup may be cooled in an ice bath and stored in the refrigerator to allow the flavors to develop.
When ready to serve the soup, preheat the oven to 350ºF.
Ladle the soup into individual ovenproof soup crocks. Top each crock with a slice of bread and sprinkle with grated cheese, covering the bread completely and coming to the edges of the crocks.
Set the soup crocks in a large baking dish and add enough boiling water to the baking dish to reach two-thirds of the way up the sides of the crocks, making a water bath. Bake until the soup is thoroughly heated, if needed, and the cheese is lightly browned, 10-15 minutes.
Serve at once.