Gooey, bubbling cheese and caramelized onions certainly make French onion soup enticing, but it is the stock that makes the difference between a great soup and a lackluster one.
Use the very best you can get your hands on; pretty much any rich, full-bodied stock will work (chicken, turkey, veal, beef, duck) and that means not using store-bought stuff that comes in cartons.
One stock that really shines is smoked chicken stock. To make it, simply use chicken stock in the drip pan underneath chickens being smoked and roasted on a charcoal grill.
Gruyere cheese (from Switzerland) is generally the go-to cheese for onion soup for its distinctive nutty tang. It is quite costly, but a good result can be had with using a half-and-half mixture of Gruyere and fontal cheese, an Italian semi-soft melting cheese.
Which alcohol you use for this recipe is really up to you. I think port wine provides the right level of body and caramel notes that enhance the onions the best.
MAKE AHEAD: The soup can be made well in advance and frozen. The baguette toasts can be made several days ahead and stored in an airtight container.
French Onion Soup
- 1 baguette, cut into 1/2-inch slices
- 2 pounds (4 medium) yellow onions, peeled, halved from top to bottom and sliced into 1/4-inch half-moons
- 4 large fresh bay leaves
- 2 tablespoons canola oil
- 2 tablespoons unsalted butter, cut into small cubes
- Freshly ground black pepper
- 1/2 teaspoon onion powder
- 8 cups homemade veal, beef, chicken stock or smoked chicken stock (see headnote)
- 1/3 cup port (may substitute Madeira, sherry or dry vermouth)
- 1 teaspoon chopped fresh thyme leaves
- 2 cups grated Gruyere cheese
- 2 cups grated fontal cheese
Preheat the oven to 375 degrees.
Spread the baguette slices in a single layer on a baking sheet and bake them for 15 to 20 minutes, until lightly browned and hard.
Heat a large saute pan over medium heat for several minutes. Spread the onions evenly in the pan, along with 2 of the bay leaves, and let them sit untouched for a couple of minutes. Drizzle the oil evenly over them and dot with butter. Do not stir them for several minutes. (The goal is to let some of the onion’s moisture evaporate and to get some good color on the onions at the start. Once you stir, water will be released, and the caramelizing will end until that water evaporates.)
Stir the onions, using a flat-edged wooden spoon to scrape up all the browned bits from the bottom of the pan. Season to taste with salt and pepper. Let the onions cook, stirring often, for 20 to 25 minutes, until they are golden brown and nicely caramelized.
Transfer the onions to a large pot and add the 2 remaining bay leaves, the onion powder and the stock. Season with 1/2 teaspoon salt and 1 teaspoon pepper. Bring to a boil over medium-high heat, then reduce the heat to medium and let the soup cook, uncovered, for 15 minutes, adjusting the heat to keep it at a very slow boil.
Position a rack in the upper third of the oven and preheat the broiler to high. Line a rimmed baking sheet with aluminum foil and place 8 onion soup crocks on it.
Stir the port and thyme into the hot soup, and ladle it into the crocks stopping a half-inch short of their rims. Discard bay leaves. Float 2 or 3 slices of baguette on top: You want to cover the surface of the soup without the bread overlapping. Combine the Gruyere and fontal cheese in a small bowl. Sprinkle 1/2 cup of the cheese mixture evenly over the toasts in each crock (don’t skimp!) and broil for 3 or 4 minutes, until the cheese is bubbling and well browned. Serve immediately. 8 servings.
Per serving: 440 calories, 21 grams protein, 29 grams carbohydrates, 25 grams fat, 13 grams saturated fat, 95 milligrams cholesterol, 670 milligrams sodium, 2 grams dietary fiber, 6 grams sugar