French Onion Soup: the Cook's Illustrated Way

"I used to caramelize the onions on the stove top, but now I use this fantastic method. Finally, a way to make genuine French Onion Soup without all of the stirring. While it still takes quite some time, the onions are roasted in the oven. Sweet onions, such as Vidalia or Walla Walla, will make this recipe overly sweet, so use Yellow or Red, or a combo of both. Use broiler-safe crocks and keep the rim of the bowls 4 to 5 inches from the broiler to obtain a proper melting of the cheeses. Cooks Illustrated chefs prefer using Swanson Certified Organic Free Range Chicken Broth and Pacific Beef Broth, tho others will do fine as well. There is actually more flavor and depth in chicken broth than in beef and that is why they combine it with the beef broth. Much of the cooking time is passive...and the aroma makes the kitchen smell divine! For the best flavor, make the soup a day or 2 in advance, it also freezes well in 2 gallon freezer bags. Prep time includes the soup and the croutons. Cooking time is approximate, please use your judgment. I make this every Christmas Eve along with appetizers and those that missed Christmas Eve INSIST on having a bowl on Christmas morning! LOL It truly is the best French Onion Soup I have ever tasted. For those special occasions, try this one. Hope you enjoy!"
photo by sefork photo by sefork
photo by sefork
photo by Jlbutler2121 photo by Jlbutler2121
photo by Jlbutler2121 photo by Jlbutler2121
photo by Bonnie G #2 photo by Bonnie G #2
Ready In:
5hrs 35mins




  • For the soup:

  • Adjust oven rack to lower-middle position and heat oven to 400°. Generously spray inside of heavy-bottomed large (at least 7-quart) Dutch oven with nonstick cooking spray.
  • Place butter in pot and add onions and 1 teaspoon salt. Cook, covered, 1 hour (onions will be moist and slightly reduced in volume).
  • Remove pot from oven and stir onions, scraping bottom and sides of pot. Return pot to oven with lid slightly ajar and continue to cook until onions are very soft and golden brown, 1 1/2 to 1 3/4 hours longer, stirring onions and scraping bottom and sides of pot after 1 hour.
  • 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 liquid evaporates and onions brown, 15 to 20 minutes, reducing heat to medium if onions are browning too quickly.
  • Continue to cook, stirring frequently, until pot bottom is coated with dark crust, 6 to 8 minutes, adjusting heat as necessary. (Scrape any fond that collects on spoon back into onions.)
  • Stir in 1/4 cup water, scraping 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 wine and balsamic vinegar, stirring frequently, until wine evaporates, about 5 minutes.
  • Stir in broths, 2 cups water, the thyme, bay leaf and parsley (tied with twine or wrapped in cheese cloth for easy removal from pot) and 1/2 teaspoon salt, scraping up any final bits of browned crust on bottom and sides of pot.
  • Increase heat to high and bring to simmer.
  • Reduce heat to low, cover, and simmer 30 minutes. Remove and discard herbs, then season with salt and pepper to taste.
  • For the croutons: While soup simmers, arrange baguette slices in single layer on baking sheet and bake in 400-degree oven until bread is dry, crisp, and golden at edges, about 10 minutes. Set aside.
  • To serve: Adjust oven rack 4 to 6 inches from broiler and heat broiler.
  • Set heat-safe soup bowls or crocks on rimmed baking sheet and fill each with about 1 1/2 cups soup.
  • Top each bowl with two toasted baguette slices (try not to overlap) and divide Swiss cheese slices, laying them in a single layer, if possible, on bread.
  • Sprinkle each serving with about 2 tablespoons grated Asiago cheese and broil until well browned and bubbly, 7 to 10 minutes.
  • If using regular soup bowls, broil the toasts and the cheese only and then place the toasts on top of the soup.
  • Cool 5 minutes and serve.

Questions & Replies

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  1. K9 Owned
    I have made other onion soups than were good, less labour intensive and confess to a fair amount of muttering during the caramelization process. "This better be good" etc. I am thrilled! This French Onion Soup is the best I have had outside of Quebec and I can't give it higher praise than that! The cooking down of the onions by this method produced a broth that cannot be duplicated using shortcuts. I am so very glad that there are only two of us and it makes enough for 6 because having this in my freezer will be wonderful for cold nights when we want something hearty and a bit special. I wouldn't hesitate to serve this to guests. Thank you so much for sharing this gem which is now the only French Onion Soup I can see myself making.
  2. OliveLover
    I was just getting ready to post this, and realized I'd not bothered to make a search. Thank you Scoutie! This is an amazing soup. I do not use the red wine in this, however, but do the final deglazing with dry sherry. I also cut my onions smaller. I find long strings of onion difficult to eat. Scoutie notes that this freezes well. I do it in quarts, which is enough to pop into the microwave to thaw and finish under the broiler for a quick week night supper with a Caesar salad. I've not tried the Asiago cheese, preferring a really good Gruyère in its place.
  3. Merlot
    Wish I could give this 10 stars! I am a connoisseur of french onion soup and this is by far the best I have ever had!!! I have never made it with the combination of beef AND chicken broth. What a difference it makes. The flavor is outstanding! I am throwing out all my other French Onion Soup recipes. Thanks for sharing, Scoutie!
  4. MaryMc
    This is really good soup! The method for caramelizing the onions is brilliant. Be warned: your house will smell like onions for days--but I don't think that's a bad thing! The asiago cheese is a nice touch, too--it blends well and adds more flavor to the Swiss.
  5. luvcookn
    ABSOLUTELY AWESOME! Finally a technique that works. I intially chose this recipe just for the technique...however, the flavour was the shining star. I made as directed...however had to sub the fresh thyme for dried, and used Merlot. Thank you Scoutie for sharing this phenomenal soup!!!


  1. Jlbutler2121
    I tried this recipe out of the rest because I am a fan of the Cook's Illustrated test kitchens. I have to say this recipe has a depth of flavour that I've only had when in France. The onions reduce and carmelite so richly that it almost seems as though your eating a hearty beef stew. <br/><br/>I subbed red wine for frozen sparkling white wine and did not have any balsamic vinegar. But the flavour of the white gave the tang it needed.<br/><br/>I used a big chunk of french bread tired with Emmental cheese and grilled it to just before burnt and crispy. I highly recommend truong this recipe for an authentic rustic country soup.


<p>Hello all, being from California, I can honestly say I am a foodie. You can walk by construction workers here and hear them saying things like, So I used some fresh garlic and olive oil, then threw the rest into the pan to sautee. LOL I love all kinds of food, and trying to eat healthier as I get older, but still indulge in the occasional deep-fried food or sweet. <br />I LOVE this site! I have 3 or 4 other food sites such as Epicurious and Food Network, but I always come back here! The ease and all of the features just can't be beat. <br />Thanks Zaar and I look forward to participating more.</p>
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