Monday, March 1, 2010

French Onion Soup, According to Cook's Illustrated

French onion soup has been on Erik's "to cook" list for a while now, and last night we finally got around to it.  There are so many recipes out there to choose from, but essentially they all start with caramelizing onions, adding  some sort of booze, a variety of broths, some herbs, and letting it simmer all together.  Then of course the thing that makes it French onion soup, not just any old onion soup, is the melting of copious amounts of cheese all over the top.  But which recipe to choose?  One of my fave blogs, Brown Eyed Baker, had recently featured a French Onion Soup, following a recipe from Cook's Illustrated, which might as well be the Bible, so I figured, might as well start with the best.  

What made the Cook's Illustrated version so appealing was that they took about four times longer to caramelize the onions, so I figured those would end up being some damn delicious onions.  And oh boy, were they ever.  Instead of doing everything stove-top, CO has you cook the onions down for 2 1/2 hours in the oven before even starting the stovetop caramelizing, which made those onions so sweet it was hard to believe I wasn't eating candy.  Not even hyperbole, I swear.  Then a mixture of beef and chicken broths, and water, thyme and a bay leaf, and we were simmering.   

Now, it might be sacrilege to admit this, but actually the only thing I don't like about French onion soup is that excessively cheesy crust.  Maybe it's my inner moderately-health-conscious person talking here, but just seeing all that oozy cheese all over the place just doesn't do it for me, plus it always makes a mess and inevitably you burn your tongue on it.  And in fact, Cook's Illustrated agrees with me!  So as a variation, we toasted slices of french bread on both sides under the broiler, then topped one side with grated Gruyere, and melted that for a minute, and floated those big cheese croutons atop the soup.  The soup quickly saturated the crouton and helped melt the cheese, making it, for me, the perfect topping for an exceptional soup.  But no matter how you like to finish it, either drenched with cheese or delicately topped with a modest amount this soup is a winner.  It takes a bit of time, but it's a fun project for a Sunday afternoon (or whenever you have time).  From start to finish the soup took about 4 hours, but the first 2 1/2 is just oven time, and your patience will certainly be rewarded.

French Onion Soup (from Cook's Illustrated)
Serves 6

3 Tablespoons of unsalted butter, cut into 3 pieces
* 4 pounds of yellow onions, peeled, halved, and cut into 1/4 inch thick slices
* Salt
* 3 cups water, divided
* 1/2 cup dry sherry (we used a dry white wine)
* 4 cups of chicken broth
* 2 cups of beef broth
* 6 sprigs of fresh thyme, tied in a bundle with kitchen twine
* 1 bay leaf
* Freshly ground black pepper
* Baguette, cut into 1/2 inch slices
* About 2 cups of shredded Gruyere cheese

1.  Adjust oven rack to lower-middle position and preheat the oven to 400 degrees F.  Generously spray the inside of a heavy bottomed large (7 quarts, at least) Dutch oven with nonstick cooking spray.  In the Dutch oven combine sliced onions, butter, and 1 teaspoon salt.  Cover and cook in oven for 1 hour.  After an hour, remove from oven and stir, being sure to scrape the bottom and sides of the pot.  At this point the onions will be moist and slightly reduced in volume.  Return the Dutch oven to the oven with the lid ajar and continue to cook for an additional 1 1/2 hours until the onions are very soft and turning golden brown, stirring onions and scraping down Dutch oven again after 1 hour.

2.  After a total of 2 1/2 hours in the oven, transfer pot to stove top over medium-high heat.  Cook onions, stirring frequently and scraping bottom and sides of the pot, until accumulated liquid has evaporated and onions start to brown more, 15 to 20 minutes, reducing heat to medium if onions are browning too quickly.  Continue to cook, stirring frequently, until the bottom of the pot is coated with a dark crust, 6 to 8 minutes.  Scrape any crust that sticks to the spoon back into the onions.

3.  Deglaze pan by stirring in 1/4 cup of water, and scraping the bottom of the pot to loosen crust.  Cook until water evaporates and the pot bottom has formed another dark crust, 6 to 8 minutes.  Repeat process of deglazing an additional 2 or 3 times (3-4 times total), until onions are very dark brown.  (Taste them now, they are like candy!).  Perform a final deglazing with the sherry, stirring frequently until sherry evaporates, about 5 minutes.
4.  Stir in broths, 2 cups water, thyme, and bay leaf, scraping up any final bits of browned crust.  Increase heat until broth begins to simmer (a few bubbles breaking the surface every few seconds), then reduce heat and simmer, covered, for 30 minutes.  Remove and discard herbs, then season to taste with additional salt and pepper, if desired.

5.  While soup is simmering, prepare the croutons.  Arrange baguette slices in a single layer on a cookie sheet and bake at 400 degrees for 10 minutes until the bread is dry and lightly browned.

6.  Time to put it all together: If you have individually sized broiler-safe crocks to serve the soup in, proceed thusly:  Adjust oven rack 6 inches below broiler element then preheat broiler.  Set crocks on a cookie sheet and fill each with soup, but not all the way to the top.  Top each crock with a single layer of baguette, 1 or 2 slices of baguette, and sprinkle evenly with cheese.  Carefully transfer the cookie sheet to the oven and broil for 3-5 minutes, until the cheese is melted and bubbly.  Let cool for 5 minutes before serving.

If you do not have broiler safe crocks (we didn't), just arrange the baguette slices on the cookie sheet, sprinkle evenly with cheese, and broil until the cheese is melted and bubbly.  Remove from the oven and place 1 or 2 croutons atop each bowl and serve.  Enjoy!!! 


  1. Isn't this absolutely fabulous?! My new favorite soup :) Glad you liked it as well!

  2. Looks delicious - can you make me some?? BTW the melty topping is the best part, I don't know what you're talking about.