Easy French Onion Soup

5 from 5 votes

Slowly caramelized onions simmered in a rich beef broth, then topped with toasted baguette and bubbling melted cheese. It takes one pot and a handful of simple ingredients, and the base can be made days ahead.

Course Dinner, Lunch

Cuisine French

Keyword best french onion soup recipe, easy french onion soup, French Onion Soup

Prep Time 15

Cook Time 1 15

Total Time 1 30

Servings people

Calories 293kcal

Author Blair Lonergan

Ingredients

2 tablespoons salted butter
3-4 large Vidalia onions (about 3 lbs. total), peeled and sliced
1 clove garlic, peeled and minced
2 teaspoons minced fresh thyme (or ½ teaspoon dried thyme)
8 cups beef broth (or beef stock)
1 tablespoon Worcestershire sauce
1 bay leaf
1 tablespoon balsamic vinegar
Kosher salt and ground black pepper, to taste
1 baguette, sliced into ¾-inch thick rounds
8 ounces Swiss or Gruyere cheese, shredded

Instructions

Caramelize the onions: Melt the butter in a large Dutch oven or soup pot over medium heat. Add the onions and saute for 20 minutes, stirring frequently, until deep golden and reduced to about a third of their original volume.
Add the garlic: Stir in the minced garlic and saute 10 minutes more, stirring often so nothing scorches.
Deglaze the pot: Add the thyme and 1 cup of the beef broth, stirring and scraping to loosen the browned bits from the bottom of the pot.
Build and simmer the broth: Add the remaining beef broth, Worcestershire sauce, and bay leaf. Increase the heat to medium-high and bring to a boil. Reduce the heat to low and simmer for 20 to 30 minutes.
Finish and season: Stir in the balsamic vinegar, discard the bay leaf, and season with salt and pepper to taste.
Toast the bread: While the soup simmers, adjust an oven rack to the middle position and heat the oven to 400°F. Arrange the bread slices on a baking sheet and toast just until barely browned, about 5 minutes. Remove and set aside.
Fill the bowls: Switch the oven to broil. Place oven-safe soup bowls on a rimmed baking sheet and ladle in the soup.
Add the topping: Top each bowl with 2 slices of toast and sprinkle with about 1/4 cup of the shredded cheese.
Broil: Place the baking sheet on an oven rack about 6 inches from the heat and broil for 2 to 3 minutes, until the cheese is melted and bubbly. Watch closely so the bread and cheese do not burn.

Notes

Onion doneness is the whole game. Look for deep golden color and onions collapsed to about a third of their starting volume, not just softness.
Use a good broth. Bouillon leaves the soup tasting salty but empty, since the broth carries half the flavor.
Season at the end. Broth saltiness varies, so taste before adding salt and adjust from there.
No wine required, but you can replace 1/2 cup of the beef broth with a dry white such as Pinot Grigio or Sauvignon Blanc. Red works too.
Onion swaps: yellow onions make a less sweet, more traditional soup, and red onions bring a bolder flavor.
Cheese swaps: Comte, provolone, mozzarella, fontina, Gouda, and Parmesan all melt well in place of Swiss or Gruyere.
No oven-safe bowls? Broil the cheese-topped toast on a sheet pan and serve it alongside the soup for dipping.
Make ahead and storage: refrigerate the soup base without the topping for 2 to 3 days, or freeze up to 3 months. Reheat over low heat, then add fresh toast and cheese and broil.

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