French onion soup is one of the great pleasures of my life; rich beefy broth, sweet soft onions, buttery bread, and gooey crusty cheese, Really, how could you not like this? It is ultimate comfort food, if you can get someone else to make it for you that is. Because if you want to make this for yourself to comfort you on a cold night or after a long day, by the time this recipe is ready you will have forgotten why you wanted to make it for yourself in the first place. Don’t let that scare you away though. All I am saying really is that this recipe requires some planning and forethought. If you can muster that up, this soup is totally worth the effort and you will be so pleased with yourself as soon as you taste that first spoonful.

This recipe comes from my good friend Tommy; that would be Thomas Keller to you all. Okay, he’s not really my friend, but this is my blog and that means that I can type anything I want and pass it off as truth. So, in imafoodblog land Tommy Keller is our friend. :yes:

Image from Amazon

I have owned the Bouchon cookbook by Thomas Keller for quite a while but Nick and I have only cooked one or two recipes from it. His recipes are not very figure friendly so I don’t have too many occasions to use the book. And when I volunteered to host Recipes to Rival for October, I did not have a particular recipe in mind. Though I had been thinking about making some real French onion soup for a few weeks, and that seemed like a perfect fall weather R2R challenge.

Bouchon and the accompanying Bouchon Cookbook features French bistro food. I don’t think you can get more French bistro than onion soup, and I know that Thomas Keller does not do anything half-assed. So I figured his recipe for onion soup would be delicious and authentic, which is exactly what I wanted to accomplish with my first attempt at this soup.

I made this soup twice. The first attempt came out wonderfully. However, I knew I could do better. The first time I made this I did not read ahead enough to see that Keller calls for homemade beef stock in his recipe and pretty much says that he would rather you use water than substitute canned stock for the homemade stuff. I was worried if I used only water the broth would not be rich enough, so I met Tommy halfway and used half water and half store bought stock. I think this compromise produced a very good end result, and I would make it this way again for sure.

But I kept thinking about the homemade beef stock. I had never made my own before, we have made plenty of chicken stock in our little kitchen, but never beef stock. So I decided that I had to make it again and go all out and make Keller’s homemade beef stock as well. I got myself some meaty leg bones from my butcher and made my very first homemade beef stock. It came out great! The aroma that wafted through our apartment as it simmered for 6 hours let me know that canned beef broth should not even be in the same category as the real stuff. The smell was amazing. I definitely won’t make it every time I need beef stock, but I will whenever beef stock will be one of the main flavors in my dish, like this soup!

The second batch of soup with the homemade stock was AMAZING. Right now it is Sunday and I finished the soup today and had a taste so I could write about it. It had a depth of flavor that the first batch lacked. I am “aging” the finished soup in the fridge until Tuesday since Keller says it gets even better if left to sit for a day or so. I did this so I could get the total full effect of what Keller expects this soup to be, and also for scheduling reasons I need a dinner on Tuesday that I can pull together really quickly. I will update the post once I have a full bowl with cheese and all. I know it’s going to be great though! I am excited to eat it.

The recipe for both the beef stock and the onion soup are after the jump, along with some process photos. Take a deep breath and tell yourself it will be worth it in the end, because this is a long one folks. It is truly not complicated, but I am not going to lie and say it’s a cinch to make. It requires some effort, tender love and care, but you will be rewarded in the end.

Follow up:

Onion Soup - Soupe A L’Oignon
Thomas Keller - Bouchon, with very minor changes by
makes 6 servings


  • 2 bay leaves
  • 12 black peppercorns
  • 6 large sprigs of thyme


  • 8 pounds (about 8 large) yellow onions
  • 4 tablespoons (2 ounces) unsalted butter
  • 4 tablespoons olive oil
  • Kosher salt
  • 1 1/2 teaspoons all purpose flour
  • 3 1/2 quarts Beef Stock (recipe below)
  • Freshly ground black pepper
  • Sherry wine vinegar or white wine/champagne vinegar


  • 1 baguette (about 2 1/2 inches in diameter)
  • Extra Virgin Olive Oil
  • Kosher salt

To Finish:

  • 6 to 12 slices (1/8 inch thick) aged Comte or Emmentaler cheese (at least 4 inches square)
  • 1 1/2 cups grated aged Comte or Emmentaler cheeses, or a combination

The more basic the soup, the more critical the details: Slice the onions uniformly and brown them very slowly and evenly; slice the bread a half inch thick and dry it completely in the oven; and serve the soup in appropriately sized bowls so that the melted cheese extends over the rim. When you hit it right, there’s nothing more satisfying to cook or to eat than this soup.

It’s worth reiterating the importance of cooking the onions slowly so that the natural sugars caramelize rather than brown through high heating sautéing. The onions cook for about five hours and need to be stirred often, but they can be made up to two days ahead. The soup is best if refrigerated for a day or two so that the flavors of the onion and beef broth can deepen.

Comte is traditionally the cheese of choice, but Emmentaler works as well. Gruyère is a bit strong. Use an aged cheese; a younger cheese would just melt and wouldn’t form a crust.

FOR THE SACHET: Cut a piece of cheesecloth about 7 inches square. Place the bay leaves, peppercorns, and thyme in the center, bring up the edges, and tie with kitchen twine to form a sachet.

FOR THE SOUP: Cut off the tops and bottoms of the onions, then cut the onions lengthwise in half. Remove the peels and tough outer layers. Cut a V wedge in each one to remove the core and pull out any solid, flat pieces of onion running up from the core.

Lay an onion half cut side down on a cutting board with the root end toward you. Note that there are lines on the outside of the onion. Cutting on the lines (with the grain) rather than against them will help the onions soften. Holding the knife on an angle, almost parallel to the board, cut the onion lengthwise into 1/4 inch thick slices. Once you’ve cut past the center of the onion, the knife angle will become awkward: Flip the onion onto its side, toward the knife, and finish slicing it, again along the grain. Separate the slices of onion, trimming away any root sections that are still attached and holding the slices together. Repeat with the remaining onions. (You should have about 7 quarts of onions)

Melt the butter and oil in a large heavy stockpot over medium heat. Add the onions and 1 tablespoon salt, reduce the heat to low. Cook, stirring every 15 minutes and regulating the heat to keep the mixture bubbling gently, for about 1 hour, or until the onions have wilted and released a lot of liquid. At this point, you can turn up the heat slightly to reduce the liquid, but it is important to continue to cook the onions slowly to develop maximum flavor and keep them from scorching. Continue to stir the onions every 15 minutes, being sure to scrape the bottom and get in the corners of the pot, for about 4 hours more, or until the onions are caramelized throughout and a rich deep brown. (Sara’s note - like a super deep brown, like way browner than you think they need to be. Think poop. Yes I said it.) Keep a closer eye on the onions toward the end of the cooking when the liquid has evaporated. Remove from the heat. (You will need 1 1/2 cups of onions for the soup; reserve any extra for another use. The onions can be made up to 2 days ahead and refrigerated.)

Transfer the caramelized onions to a 5 quart pot (if they’ve been refrigerated, reheat until hot.) Sift in the flour and cook over medium-high heat, stirring, for 2 to 3 minutes. Add the beef stock and sachet, bring to a simmer, and simmer for about 1 hour, or until the liquid is reduced to 2 1/2 quarts. Season to taste with salt, pepper, and a few drops of vinegar. Remove from the heat.

FOR THE CROUTONS: Preheat the broiler. Cut twelve 3/8 inch thick slices from the baguette (reserve the remainder for another use) and place on a baking sheet. Brush the bread lightly on both sides with olive oil and sprinkle lightly with salt. Place under the broiler and toast the first side until golden brown, then turn and brown the second side. Set aside and leave the broiler on.

TO COMPLETE: Return the soup to a simmer. Place six flameproof soup tureens, with about 1 1/2 cups capacity on a baking sheet to catch any spills (the soup will bubble up and over the tureens). Add the hot soup to the tureens, filling them within 1/2 inch of the tops. Top each serving with 2 croutons: Lay them on the surface - do not push them into the soup. Lay the slices of cheese over the croutons so that the cheese overlaps the edges of the tureens by about 1/2 inch, Scatter the grated cheese over the sliced cheese, filling in any areas where the sliced cheese is thiner, or it may melt into the soup rather than forming a crust.

Place the tureens under the broiler for a few minutes, until the cheese bubbles, browns, and forms a thick crust. Eat carefully, the soup and tureens will be very hot.

Okay now if you are feeling like a real challenge, you can make Keller’s homemade beef stock as well. I had never made homemade beef stock before this, and I found it to be very easy and worth the effort for this soup.

Beef Stock
Thomas Keller - Bouchon
makes 3 1/2 quarts

We use this stock for onion soup and to add in combination with veal stock to beef stews. The bones are roasted first to give the stock a roasted flavor, then simmered with caramelized vegetables for a rich brown stock.

  • About 2 tablespoons canola oil
  • 5 pounds meaty beef necks or leg bones
  • 2 small Spanish onions (about 8 ounces total), peeled
  • 1/2 teaspoon Kosher salt
  • 3 ounces (1 large) carrot, peeled and cut into 4 pieces
  • 3 ounces (1 large) leek, roots trimmed, split lengthwise, rinsed well, and cut into 2 inch pieces, or leek tops
  • 1 large sprig of thyme
  • 1 large sprig of Italian parsley
  • 3 bay leaves
  • 1/4 teaspoons black peppercorns
  • 1 head garlic, cut horizontally in half

Preheat the oven to 475F. Place a large roasting pan in the oven to preheat for about 10 minutes.

Add 1 tablespoon of the oil to the hot roasting pan and distribute the beef bones in a single layer. Roast the bones for about 45 minutes, or until richly browned, turning each piece only after it is well browned on the bottom side.

Meanwhile, cut 1 onion crosswise in half. Heat a small heavy skillet over medium-high heat for 2-3 minutes. Place 1 onion half cut side down to one side of the skillet so that it is not over direct heat and let it brown and char black, about 30 minutes. This will add color to the stock, set aside.

Remove the roasting pan of bones from the oven and reduce the oven temperature to 400F. Transfer bones to a large colander set over a baking sheet to drain.

Drain the fat from the roasting pan and discard. Add about 1 cup water to the pan, place over medium heat, and use a metal spatula to scrape the bottom of the pan and release the pan juices. Let them simmer until reduced by half. Add the resulting fond to a large deep stockpot.

Transfer the bones to the stockpot and add about 5 quarts cold water - just enough to cover the bones. Any fat present in the juices will rose to the top when the cold water is added; use a skimmer to remove and discard the fat. Add the charred onion half and the salt. Place over medium heat and bring to a simmer, skimming as impurities rise to the top of the stockpot. Reduce the heat and simmer gently, skimming often, for 5 hours. If the level of liquid falls below the bones, add additional water.

This is why you skim skim skim. That is fat.

Meanwhile, cut the remaining whole onion into quarters and cut the remaining onion half in half again. Place the onions, carrots, and leeks in a roasting pan that will hold them in a single layer, toss with the remaining 1 tablespoon canola oil, and place in the oven to roast for 20 minutes.

Remove from the oven and stir, then roast for an additional 20 minutes or until the vegetables are richly caramelized. Set aside.

After the stock has simmered for 5 hours, add the caramelized vegetables, herbs, peppercorns, and garlic and simmer for 1 hour longer. Turn off the heat and allow the stock to rest for 10 minutes.

Prepare an ice bath. Place a strainer over a large bowl. Removing the bones or pouring out the liquid through the bones would cloud the stock. Instead, carefully ladle the stock out of the pot and pass it through the strainer, tilting the pot as necessary to get all the stock. Strain a second time through a chinois or fine mesh strainer lines with a dampened cheese cloth.

This is after the first strain.

This is the cheesecloth after the second strain, this is why this is a super important step.

Measure the stock. If you have more than 3 1/2 quarts, pour it into a saucepan and reduce to 3 1/2 quarts. Strain the stock into a container and cool in the ice bath, stirring occasionally. (Store the stock in the refrigerator for up to 3 days, or freeze in several containers for longer storage.)

NOTE: If the stock will be refrigerated for longer than 3 days, bring it back to a boil after 3 days, cool it, and return it to the refrigerator.