French Onion Soup

3.80 from 10 reviews

Learn how to make classic French Onion Soup like a restaurant Chef! Made with caramelized onions, a rich savory broth and toasted cheesy bread, this flavorful soup is ridiculously easy to make, inexpensive and better than any store bought version out there! Vegetarian Adaptable, Gluten-Free Adaptable. It can be made without wine or sherry.

Course Dinner, Soup

Cuisine French

Keyword Classic French Onion Soup, Classic French Onion Soup Recipe, Easy French Onion Soup Recipe, Homemade French Onion Soup, How to Make French Onion Soup, Traditional French Onion Soup

Prep Time 20

Cook Time 1 30

Total Time 1 50

Servings servings

Calories 691kcal

Author Chef Kathy McDaniel

Ingredients

4 tablespoons butter (unsalted or salted)
1 tablespoon olive oil or vegetable oil
3 pounds onions (see notes) peeled, halved and thinly sliced (about ⅛-thick) yellow onions or sweet Vidalia onions work best
¾ teaspoon Kosher or sea salt plus more to taste
¼ teaspoon freshly ground black pepper plus more to taste
3/4 cup dry white wine (replace with broth if preferred)
1 tablespoon dry sherry (replace with cider vinegar if preferred)
2 tablespoons all-purpose flour
8 cups beef broth or beef stock
1 bay leaf
2 fresh thyme sprigs or ½ teaspoon dried thyme
½ teaspoon Worcestershire sauce
1 small baguette sliced ½-inch thick
6 ounces Gruyère cheese, grated (about 1 ½ cups) (replace with Fontina or Mozzarella)
Optional: Garnish with fresh thyme leaves or chopped chives.

US Customary - Metric

Instructions

In a large pot or Dutch oven, over medium heat, add the oil and butter. When the butter has melted, add the onions, salt and black pepper. Stir.
Cook, uncovered, stirring occasionally until the onions are caramelized and deep golden brown, about 45 to 55 minutes. Times vary depending on the size and type of pot you are using and the amount of heat. Midway through the cooking process, you may need to stir more frequently. If the onions are browning too quickly, lower the heat as needed. If the onions are sticking to the pot, scrape the bottom of the pot with a wooden spoon. If needed, deglaze the pot by adding about a tablespoon of water and scraping the bottom.. This will help release the bits that are stuck. Continue cooking.
When the onions are caramelized and golden brown, add the wine and the dry sherry. Raise the heat to medium high and bring to a boil. Cook until almost all the liquid has evaporated, about 5-6 minutes. Add the flour and cook, stirring constantly for about 1 minute.
Slowly add a cup of broth while stirring constantly. Stir in the remaining broth, bay leaf, thyme and worcestershire sauce. Bring to a boil, then reduce the heat and simmer for 20 minutes.
While the soup simmers, preheat the oven to 400ºF. Set the oven rack in the middle position. Place bread slices in a single layer on a sheet pan and bake until the bread is crisp and golden on the edges, about 8-10 minutes.
When the soup is done simmering,remove the bay leaf and thyme sprig. Taste and adjust seasoning (please see Chef’s notes).
To broil the cheese topping, set an oven rack about 6-inches below the heat source. Turn on the broiler (on low or high).
Arrange individual ovenproof soup bowls or individual casseroles on a baking sheet. Divide the hot soup among the bowls.Cover the top with bread slices (1-2 slices depending on size). Make sure the bread doesn’t overlap. Sprinkle generously with Gruyere cheese.
Broil until the cheese melts and starts browning around the edges. Watch it carefully as the broiler browns things quickly.
If you don’t have any ovenproof soup bowls, top the toasted bread with cheese and broil until melted and bubbly. Top each soup bowl with some cheese toasts.

Notes

Onions come in many sizes so it’s hard to figure out how many onions come in a 3 pound bag; however, a large onion the size of a softball can weigh 8 to 10 ounces each. Medium onions the size of a baseball or orange can weigh 6 to 8 ounces each.
Because all onions are not created equal, you may need to make some adjustments to the seasonings to your taste.
For deeper flavor, add a few dashes of Worcestershire sauce.
For a boost of flavor, add about 1 teaspoon of beef bouillon.
If it tastes a bit bitter, add a ¼ to ½ teaspoon of sugar.
Make sure the soup is hot when you pour it into the ovenproof bowls for broiling.
The alcohol in the wine and sherry completely cooks off, making this a family-friendly meal.
If preferred, substitute the wine with additional broth and the dry sherry with cider vinegar to make French Onion Soup without wine (or any alcohol).
Make vegetarian French onion soup by using vegetable broth.
Chicken broth can replace the beef broth.

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