Sunday Cookbook Adventures: Bouchon's Onion Soup

One more post from Bouchon, finishing what I started when I made Thomas Keller's Beef Stock last week by turning it into French Onion Soup this week...

This is an interesting recipe because it is both easy and ridiculously time-consuming. After 8 hours making beef stock last weekend, I spent 8 more hours caramelizing onions yesterday, then two more hours finishing the soup today... Luckily, 95% of that time can be spent largely ignoring the cooking that's going on. This is also an interesting recipe because it is so very simple in terms of the ingredient list, which makes the quality of ingredients and the care you take with them that much more important... and which is why I would never dream of making this with anything but homemade beef stock. So, here we go with Phase 2 of the soup-making: Caramelized Onions. It turns out Thomas Keller uses a technique very similar to my standard technique only with a LOT more butter. Heh. For some reason, he has me start off with 8 pounds of onions...
I was planning to slice them on a mandolin against the grain as I usually do, but Keller recommends cutting with the grain, which is easier to do by hand. I think this actually really enhanced the final texture.
Into the pot they go with an entire stick of melted unsalted butter and some salt.
That salt is a key part of the brilliance of this method. The salt draws out the liquid from the onions in the beginning, so it can be cooked off and caramelization can proceed more evenly. (If you don't use salt at this step, the liquid continues to leech out and get in your way throughout the cooking process.) I can't remember where I first learned to do this, but I've been doing it for a few years and it revolutionized my onion-caramelizing... Here are the onions after 30 minutes:
After 3 hours:
After 4 hours:
After 5 hours:
After 7 hours:
And after 8 hours:
Mmmm... Caramelized... So, obviously the volume reduces considerably between the raw and caramelized stages... but I have no idea why Thomas Keller asked me to use 8 pounds of onions here when the recipe only makes use of a cup and a half of caramelized onions. Here's the yield from my 8 pounds:
This is something about Thomas Keller that always makes me chuckle. He likes to tell you to "reserve any extra for another use." In this case, it takes the same amount of work to make 4 cups of caramelized onions as it does to make a cup and a half, and they freeze well so I'm happy to have them... but he does this all the time. With the salmon recipe I made last year from the French Laundry Cookbook he wanted me to buy a whole side of salmon, mutilate it to get 4 perfect serving pieces cut, and then reserve the rest for another use... With the beef stock, he wanted me to slice a head of garlic in half crosswise, use one half in the stock, and reserve the rest for another use... And, yeah... this week I'm supposed to reserve "any extra" (which is two and a half cups of caramelized onions) for another use. Oh, Thomas... Anyway... Back to the soup. The onions are combined with a little flour and cooked for a few minutes.
Then a sachet containing a couple bay leaves, black peppercorns, and thyme sprigs is added, along with the beef stock.
And that's pretty much it until the plating... Just simmer for an hour or so, add a couple drops of nice sherry vinegar to taste, and call it "soup."
I used a "rustic loaf" from Russo's for the croutons, which are toasted up under the broiler just before service,
then placed atop the onion soup ready to be topped with cheese:
(Apologies for not having proper onion soup crocks... It was my first time...) I used a beautiful Gruyere from Russo's to top the croutons that topped my soup. When I told the cheese lady that I was making French Onion Soup she got a big smile on her face and exclaimed, "Oh! Wonderful! Fantastic!" and went straight for a chunk of this Gruyere to cut me a sample. So. Freaking. Good. I love the Russo's cheese lady.
After a round in the broiler, we were good to go.
This soup was really fantastic. The stock was well worth the time it took to make, the onions were awesome, and the cheese was perfect. I think Thomas Keller may have wanted me to use even more cheese, but I'm not sure I would change a single thing (other than buying the proper serving dishes) next time I make this... and there will definitely be a next time. I also had these gorgeous hanger steaks from Blood Farm:
which I turned into Steak Frites for me and my friends. There were a couple hiccups with this course, relating to a malfunctioning meat thermometer and lack of familiarity with this cut, which is one that Keller recommended. (I actually think this would be the perfect cut to sous vide and then sear. The rib-eyes lost too much texture, but these have a lot of toughness that could stand up to the technique, and marbling that would melt beautifully during sous vide cooking.) Things still turned out lovely and delicious, but a couple of the steaks weren't cooked as well as I would have liked. That's what I get for experimenting on my friends, I guess... Trying not to dwell on that, and instead focus on the yummy, yummy soup... Plus, pretty:
Despite a couple technical difficulties with the main course, it was fun to share this meal with friends. Even though there was almost 18 hours of prep involved in the stock and the onions, this is still a nice meal for entertaining since all of the work can be done in advance and is very low-maintenance, leaving only about 15 minutes of work when your guests arrive. Good stuff...