The Best French Onion Soup (…ever!)

The last recipe I posted for French Onion soup was from Cook’s Illustrated and the soup came out great. So when I saw that they had an updated recipe, I had to give it a try. The big change between the recipes was that the updated version calls for caramelizing the onions in the oven rather than on the stove top. This change lets you get a lot more flavor out of the onions and means you don’t have to stir the onions every minute. They call this, “The Best French Onion Soup,” and after trying it, I can’t argue!


The Best French Onion Soup

From: Cook’s Illustrated

Serves 6


For the best flavor, make the soup a day or 2 in advance. Alternatively, the onions can be prepared through step 1, cooled in the pot, and refrigerated for up to 3 days before proceeding with the recipe.


  • 3 tablespoons unsalted butter , cut into 3 pieces
  • 6 large yellow onions (about 4 pounds), halved and cut pole to pole into 1/4-inch-thick slices (Make sure you get Yellow)
  • Table salt
  • 2 cups water, plus extra for deglazing
  • 1/2 cup dry sherry
  • 4 cups low-sodium chicken broth (They recommend Swanson Certified Organic Free Range Chicken Broth )
  • 2 cups beef broth (They recommend Pacific Beef Broth)
  • 6 sprigs fresh thyme , tied with kitchen twine
  • 1 bay leaf
  • Ground black pepper

Cheese Croutons

  • 1 small baguette , cut into 1/2-inch slices
  • 8 ounces shredded Gruyère cheese (about 2 1/2 cups)


For the soup:

  1. Adjust the oven rack to the lower-middle position and heat the oven to 400 degrees.
  2. Generously spray the inside of a heavy-bottomed large (at least 7-quart) Dutch oven with a nonstick cooking spray. Place the butter in the pot and add the onions and 1 teaspoon salt. Cook, covered, for 1 hour (the onions will be moist and slightly reduced in volume). Remove the pot from the oven and stir the onions, scraping the bottom and sides of the pot. Return the pot to the oven with the lid slightly ajar and continue to cook until the onions are very soft and golden brown, 1 1/2 to 1 3/4 hours longer, stirring the onions and scraping bottom and sides of pot after 1 hour.
  3. Carefully remove pot from oven and place over medium-high heat. Using oven mitts to handle pot, cook onions, stirring frequently and scraping bottom and sides of pot, until the liquid evaporates and the onions brown, 15 to 20 minutes, reducing the heat to medium if the onions are browning too quickly. Continue to cook, stirring frequently, until the pot bottom is coated with a dark crust, roughly 6 to 8 minutes, adjusting the heat as necessary. (Scrape any fond that collects on spoon back into onions.)
  4. Stir in 1/4 cup water, scraping the pot bottom to loosen crust, and cook until water evaporates and pot bottom has formed another dark crust, 6 to 8 minutes. Repeat process of deglazing 2 or 3 more times, until onions are very dark brown. Stir in the sherry and cook, stirring frequently, until the sherry evaporates, about 5 minutes.
  5. Stir in the broths, 2 cups of water, thyme, bay leaf, and 1/2 teaspoon salt, scraping up any final bits of browned crust on bottom and sides of pot.
  6. Increase heat to high and bring to simmer. Reduce the heat to low, cover, and simmer for 30 minutes. Remove and discard herbs, then season with salt and pepper.

For the croutons:

  1. While the soup simmers, arrange the baguette slices in single layer on baking sheet and bake in a 400-degree oven until the bread is dry, crisp, and golden at edges, about 10 minutes. Set aside.

To serve:

  1. Adjust oven rack 6 inches from broiler element and heat broiler. Set individual broiler-safe crocks on baking sheet and fill each with about 1 3/4 cups soup. Top each bowl with 1 or 2 baguette slices (do not overlap slices) and sprinkle evenly with Gruyère. Broil until cheese is melted and bubbly around edges, 3 to 5 minutes. Let cool 5 minutes before serving.

Equipment Used:





638 thoughts on “The Best French Onion Soup (…ever!)

  1. It really is the best! My go to for the last 11 years. It’s amazing. Making it right now. Smells amazing! Thanks for sharing!

  2. We love this recipe! It rivals any we had in Paris last year. I don’t use chicken broth in mine and usually use a port instead of Sherry. Made it today during our 5th Sunday of quarantine and dreamed of walking the streets of Paris…. it was definitely a mood lifter!

  3. Best recipe I have used to make french onion soup. It is always a hit and worth the time it takes to prepare. Enjoy it more than our very popular steak house recipe and much cheaper.

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  6. I use left over beef gravy (prime rib or something similar) as the liquid, it has the beef flavor and the thickener already combined. In fact I save extra gravy just for this.

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  8. No chicken stock in a F/O soup. Take the time and make veal stock at home and freeze in 3 cup containers. Also sherry? A nice dry Rhone white is much nicer. Slices of Gruyere also work better when baking to create a layer of toasty browned cheese. You can even layer with swiss if you want an interesting combination.

    • Thanks!
      Home-hand-made stock is not optional, it is essential for the soup to truly French. And, of course, not chicken.

      But, as you can read, some of the people are comparing this to a factory product from Panera, (a chain, I believe), so we’re really in two different worlds.

      But, what is meant by “Swiss”? Gruyere is as “Swiss” as cheese gets.

  9. Struggling with the right words to express how pleased I am with this recipe! So close to the $5 french onion soup I order at Panera that I can now make for pennies. If you are doubtful like I was, you MUST try this recipe. I did adjust with another splash of sherry, a little butter and a little sugar since my onions were not that sweet. I feel like a professional chef serving this, so thank so much for sharing.

  10. I agree with Danielle. I have been using this recipe for several years and I generally buy 10 to 20 lbs of onions so I can make enough for friends and family. It does require effort as any great dish would but I would recommend you give it another try Patty for once you get it down you will not find a better French Onion Soup anywhere!

  11. This soup is D-E-L-I-C-I-O-U-S! I’ve never made onion soup before and the directions were easy to follow. I had home-made chicken broth and also used that instead of the water. I didn’t have sprigs of thyme but sprinkled some ground thyme in. I also didn’t have sherry but put in a splash of lambrusco and it was good, with or without. It was very time consuming but I did other things in-between. I just set a timer when it needed to be stirred. Will I make it again? Yes!!!

  12. I couldn’t disagree more. Yes it is labor intensive, but it is by far the best French onion soup I have ever had. I usually leave it in the over through out the day and stir it every few hours. I also use provolone cheese.

  13. I was not impressed, it was very labor intensive, time consuming and the taste wasn’t that great. Maybe after sitting a few days in the frig it will be better.

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