I love French onion soup. The rich broth, the crouton soaking up the rich broth, the gooey melted cheese - wonderful!
It is not, however, easy to find a really good onion soup. Even in Paris, where you would expect every bistro to have a tasty version of this iconic dish, the quality ranges from tasteless to acceptable. The best I ever had was a restaurant in Seattle. It's all a little fuzzy now, because this was in the '70's, but I remember this small restaurant downtown which had a soup that was the right blend of hearty broth, silky onions and lots of cheese.
I have tried several recipes for the soup, some of which have disappointed me in one way or another, but I keep looking. This week, I tried the recipe from Thomas Keller's "Bouchon." A bit intimidating, it calls for homemade beef stock made from roasted beef bones, onions cooked slowly for 5 hours until deeply caramelized and then the stock and onions combined for another hour to reduce and deepen the soup. I admit that the idea of making my own beef stock put me off a bit, so I found an organic beef broth that had nothing unpronounceable in it and used that instead. I did caramelize the onions for hours, stirring every 15 minutes until they reached this point:
They were practically melted after 6 hours of cooking. I used a diffuser, which allowed me to keep a pretty constant low simmer without having to readjust the temperature on the cooktop. I started with 8 pounds of onions, which took me about 45 minutes, including tear breaks, to slice (I wish my knife skills were better!). They filled to overflowing a 5-6 quart pan, so there were a lot of onions to cook down. I used a mix of yellow and sweet onions, which seemed to work pretty well.
When the onions were done, I added the beef broth and some seasonings and simmered that for another couple hours. The recipe said one hour to reduce by 1/3, but it took longer than that, maybe because I kept the temperature pretty low. The result? Not bad at all. The onions were silk, the broth was deeply flavorful. With a toasted crouton and some Emmenthaler cheese melted over the top, I had something was pretty darn close to my memory and quite a bit better than most of the onion soups I've had in recent years. Time and patience paid off. Next time, maybe I'll do the stock as well!