French Onion Soup

I still remember my first bowl of French onion soup. It was January of 1978, and I was in New York City with the MIT Concert Band, the first stop of a week-long tour of the northeast. My friends and I had a free afternoon, so we wandered up Fifth Avenue from Grand Central Station. We saw a promising looking and inexpensive spot for lunch, a small restaurant called La Potagerie, and decided to try our luck. It was an upscale soup kitchen: you ordered at the counter and brought a tray with your food to an open table.

Since we were in a French-named eatery, I figured I should order something French, and what could fit that description better then French onion soup? I wasn’t sure what to make of the cheese-covered crock that was served to me, but I dug in and immediately fell in love with the melted, nutty cheese, rich broth, crunchy crouton, and sweet onions. I returned to La Potagerie whenever I could, until it closed a few years later. It was only when researching the history of the restaurant for this post that I learned it was the only restaurant opened by culinary legend Jacques Pepin – no wonder the soup was so good.

One of the first recipes I tried to cook out of volume one of Mastering the Art of French Cooking was soupe à l’oignon, a lengthy affair that required hours of cooking onions, and fresh beef stock, which I had no idea how to make. While the resulting dish met the basic requirements, it fell short on flavor, a failing I attributed to my using canned beef broth. Every few years, when the whim struck me, I’d try making the soup again, always using homemade beef stock, and always with lackluster results. Alton Brown’s method, which has you cooking the onions in an electric skillet, missed the mark, as did the Cook’s Ilustrated method which uses red onions (although, to be fair, it was pretty good). Still, nothing approached that platonic ideal that I had tasted decades ago.

I had given up on making onion soup when I received a call from my friend Colman, who was in a panic about cooking onions for his soup, which used Thomas Keller’s Bouchon recipe. I wrote about the particulars here, including tasting Keller’s soup, which restored my faith in the dish.

While assembling ingredients for ramen broth, I realized I could double up on the beef bones and use half of them to make beef stock. I’d use Keller’s method, I have done before, and then decide what to make with it. A few days later I decided it was time to try the onion soup again, using the same Bouchon recipe that gave Colman so much trouble. At least I knew what I’d be getting myself into.

Most of the recipes I’d used before call for about two pounds of sliced onions. Keller calls for eight pounds, or approximately sixteen large yellow onions.

There is a whole paragraph in the recipe devoted to how to slice the onions, the most important detail of which is to slice from pole to pole “with the grain,” instead of crosswise (saggital instead of coronal, for my biology geek readers). Thirty two trimmed and peeled onion halves could take a while to cut, so I tried a shortcut and sliced most of them on a mandoline.

I realized that not wanting to julienne my fingertips was slowing me down, so I switched back to my trusty knife, which turned out to be faster.

An hour later I had a whole lotta onions, which I transferred to my sixteen-quart stock pot containing four ounces of melted butter

I added a tablespoon of salt, reduced the heat to low, and stirred every fifteen minutes for an hour until the onions wilted and released their juices. At this point, Keller suggests turning up the heat slightly and continuing to stir every fifteen minutes for another four hours, but this is where I ran into the same problem that Colman faced. Having invested so much time and labor into getting the onions started, I was loath to raise the heat for fear of turning everything into a scorched mess. After four hours, I transferred the greatly reduced mass of onions to an enameled cast iron dutch oven, figuring it would be better at regulating the heat and would be easier to stir than the tall stock pot.

The onions started to brown after another two hours.

After two more hours they had turned a rich chocolate brown and required constant stirring.

During this last stage, I returned the beef stock – more like beef aspic after its time in the fridge – to a pot to heat.

At this point in the recipe I realized that I only needed half of the onions I had prepared for the soup, and that the other half could be “reserved for another use.” Why did I start with twice the amount? I think it’s required to provide enough mass to allow a longer cooking time. I reserved my unneeded onions in the freezer and sprinkled one and a half teaspoons of flour over the remainder, stirring to cook over medium heat for about three minutes.

I added the liquified beef stock and a sachet of two bay leaves, twelve peppercorns, and six thyme sprigs, and simmered for an hour until the liquid reduced to two and a half quarts. I seasoned it with salt, pepper, and a splash of sherry vinegar.

After ten and a half hours of constant cooking I had the basic soup, which I let sit overnight in the fridge while it turned to onion soup Jell-O.

To assemble the final soup, I reheated the liquid to a simmer while I prepared some croutons from a baguette and laid out my cheese (Comté, cut into slices by the friendly deli worker next to the cheese counter).

I ladled the soup into thick twelve-ounce bowls (I had long ago discarded my cheap individual soup crocks) set on a baking tray.

I floated two croutons on the surface,

then covered the opening with two cheese slices per bowl. If there had been any gaps I would have filled them with grated cheese, but the slices covered perfectly.

I set the tray under the broiler until the cheese browned and formed a crust.

And how did it taste? It was the best I have ever made, a perfect balance of all the components. The broth was rich and beefy, the onions were sweet, the cheese was nutty and crisp, and the croutons soaked up just enough of the soup to soften but not turn mushy. She Who Must Be Obeyed loved it, but He Who Will Not Be Ignored expressed his displeasure, no doubt brought on by a combination of tastes he hadn’t experienced before.

It wasn’t quite as good as the soup at Bouchon, but I had expected that. I don’t have an army of commis preparing batches of high-quality beef stock from more bones that I’ll see in my entire cooking career. But now that I have the technique down, and am no longer afraid to apply more heat to the onions, I’ll be trying this recipe again this winter. I’m thinking that a shot of Marmite in the finished stock will provide the flavor boost I’m looking for.

Sources:

Onions: Whole Foods
Beef stock: Belm Utility Research Kitchen