Perhaps my all time favorite comfort food is onion soup gratinee, or Soupe à l’Oignon Gratinée . I have what you might call a passion and devotion for the stuff; I’ve been making it for over three decades. If you’re thinking about making incredibly delicious onion soup, let me first say that unless you’re willing to put the time, love and patience into it, I’d sincerely recommend going out to a good restaurant that serves it. Having said that, and if you’re still reading this instead of looking for the car keys, let’s talk onions first.
Unequivocally, my first choice for onion soup is Vidalia onions. They come into season during the spring; traditionally they were harvested in the southeast of the USA. During the season I buy 30-40 pounds of Vidalias at a time, caramelize them in 10-pound batches, put them in vacuum bags and freeze them. (Caramelized Vidalia onions are great for any number of things, including pizza toppings, and my onion-tomato-olive tartin). The first time you caramelize ten pounds of onions you’ll be shocked by the reduced volume of the rendered onions.
Even more critical than the onions is the liquid for the soup; that is, the stock. Volumes have been written about stocks used in cooking, and I know I’ve stuck my two cents’ worth in at various times in this blog. Suffice it to say, without at least a good stock (we’re talking homemade), stop right here and go get the car keys.
Over the years I’ve used chicken, beef, veal, and duck stocks for onion soup. Julia Child advocates chicken stock; Thomas Keller is a proponent of beef stock. In the 80s I read a Thanksgiving dinner recipe in Gourmet from the Essex Inn, in Connecticut which profiled War of 1812 onion soup (British version) which called for copious amounts of duck backs. For the past five years or so I’ve migrated to a 50% chicken and 50% duck stock blend. I keep a lot of both stocks in a chest freezer. Regardless of your choice of stocks, the key is a degreased, rich, and flavorful one; without that, you’re wasting your time.
The last two key ingredients are cheese and bread for a large crouton. Again, it becomes a matter of personal choice for the cheese. Keller strongly suggests an aged Comte. I like a good Gruyere or Fontina. When I photographed the onion soup for this post I had neither, so I went with the Jarlsberg in the refrigerator.
Finally, for the toasted crouton I’d avoid store bought white loaf bread, if possible. I bake, so there’s usually something interesting lying around to slice up, toast and whittle down to fit the soup bowl. Baguette size slices are ideal. Just remember, the bread is going to absorb some of the soup, and it will become an integral part of the overall culinary experience.
So let’s put this all together:
To make 1 gallon Onion Soup:
10 lbs. sweet onions, preferably Vidalia
1 stick (4oz) unsalted butter
¼ cup unbleached white flour
2 Tbsp unsalted flour
2 qt. good homemade chicken stock (I’ve been using Julia Child’s for years)
2 qt. duck stock (I like Keller’s duck stock from French Laundry cook book)
½ inch slice of bread for each bowl served
¼-½ cup Gruyere cheese, sliced thin or shredded
Peel the onions, slicing off the stem and the opposite end. Cut each onion in half from stem to top, not cross-sectionally. Place the onions cut side down and, using a sharp knife, slice along the veins. This will help cook evenly and ultimately caramelize the onions. By the time you slice up ten pounds of onions, you’ll be a pro. (Figure out in advance how to deal with tearing eyes from onions: I do this close to my range’s overhead vent; my daughter wears ski goggles).
Once all the onions are sliced, place the stick of butter in a large pot, preferably a cast iron casserole. If you don’t have one large enough to hold all the onions, start out with two pans (half the butter in each one), and cook down until you can combine all the onions in one pot. Start off with medium heat, stir and coat the onions with the melting butter. Keep stirring intermittently and keep an eye on the onions for the first 10-15 minutes. Then reduce the heat to almost low, cover the casserole with a lid that is propped open a bit. Check on the onions regularly to make sure they’re not sticking. After a half-hour or so, the onions will begin to release their water. Remove the cover, stir the onions, and reduce the heat to lowest setting on a gas range. Cook the onions about three-and-a half hours, occasionally stirring with a wooden spatula. The onions will render their water and begin turning a darker color. Standing by, increase the heat a little and stir; as I said, you’ll be amazed at the reduced volume of ten pounds of onions. When all the water is rendered, and the onions are a gorgeous, caramelized brown color, off heat and allow them to cool. Take a taste: how sweet is that?
In a large stock pot melt the 2 Tbsp butter over medium heat, add the flour and stir, cooking for several minutes to make a thick blonde roux (a thickener). Add the caramelized onions, either using all of the rendered onions or a portion, depending on how thick you like your onion soup. Combine the roux and the onions, add the two stocks and combine well. Bring everything to an active simmer, and let it cook for 45 minutes or so. Taste and season it.
Just before serving, toast the croutons. There are two schools of thoughts on the croutons. Jacques Pepin likes to put them in before he adds the soup: I’m of the school that ladles in the soup first, using the crouton as raft for the cheese. Up to you. However, once the cheese is added on top, run the soup bowls under a broiler, or place in a very hot oven until the cheese melts and slightly browns.
Either I’m a glutton for punishment, or I really like making onion soup. For me, the trouble is well worth it. And I’ve never had anyone at my table disagree with me. Of course it’s infinitely easier to consume the soup than it is to make it.